Safety of heterologous ChAdOx1-S/BNT162b2 primary schedule versus homologous BNT162b2 vaccination: Insights from an Italian post-marketing study, 2021.

During COVID-19 vaccination campaign, possible ChAdOx1-S-associated risks of thrombosis with thrombocytopenia syndrome led to implement ChAdOx1-S/BNT162b2 heterologous vaccination, despite the limited information on its reactogenicity and safety. We conducted a prospective observational post-marketing surveillance study to assess the safety of this heterologous schedule. A casually selected sample of recipients (n: 85; age: 18-60 years) of ChAdOx1-S/BNT162b2 at the vaccination hub of the Foggia Hospital, Italy, was matched with an equal sample of recipients of homologous BNT162b2. Safety was evaluated 7 days, 1 month and 14 weeks after the primary vaccination series using an adapted version of the "V-safe active surveillance for COVID-19 vaccine safety" CDC standardized questionnaire. After 7 days, local reactions were highly frequent (>80%) in both groups, and systemic reactions were less common (<70%). Moderate or severe pain at the injection site (OR = 3.62; 95%CI, 1.45-9.33), moderate/severe fatigue (OR = 3.40; 95%CI, 1.22-9.49), moderate/severe headache (OR = 4.72; 95%CI, 1.37-16.23), intake of antipyretics (OR = 3.05; 95 CI%, 1.35-6.88), inability to perform daily activities and work (OR = 2.64; 95%CI, 1.24-5.62) were significantly more common with heterologous than homologous vaccination. No significant difference in self-reported health status was recorded 1 month or 14 weeks after the second dose with BNT162b2 or ChAdOx1-S/BNT162b2. Our study confirms the safety of both heterologous and homologous vaccination, with a slight increase in some short-term adverse events for the heterologous regimen. Therefore, administering a second dose of a mRNA vaccine to the recipients of a previous dose of viral vector vaccine may have represented an advantageous strategy to improve flexibility and to accelerate the vaccination campaign.

Remitting Seronegative Symmetrical Synovitis with Pitting Oedema Following Administration of the Chadox1-S/NCOV-19 Coronavirus Vaccine.

Introduction: We describe a case of remitting seronegative symmetrical synovitis with pitting oedema (RS3PE) syndrome following administration of the ChAdOx1-S/nCoV-19 [recombinant] vaccine, suggesting a possible causal link. Case Description: A 72-year-old man presented to his general practitioner with swollen, oedematous hands and legs 2 weeks after receiving a coronavirus vaccine. He had raised inflammatory markers but remained systemically well. He was initially presumed to have cellulitis, but his symptoms persisted despite several courses of antibiotics. Deep vein thromboses, cardiac failure, renal failure and hypoalbuminaemia were ruled out. Upon Rheumatology review, he was diagnosed as having RS3PE syndrome with the Covid vaccine suspected of being an immunogenic trigger. Following initiation of steroid therapy, his symptoms improved dramatically, as is characteristic of RS3PE syndrome. Discussion: The pathophysiology of RS3PE is unclear. It is known to have various triggers and associations including infections, certain vaccines and malignancy. This case highlights that a coronavirus vaccine (ChAdOx1-S/nCoV-19 [recombinant] vaccine) is also a possible trigger. Factors that make the diagnosis likely include an acute onset of symptoms including pitting oedema in a typical distribution, age above 50, and unremarkable autoimmune serology. Other learning points from this case include the importance of antibiotic stewardship and the need to explore non-infectious causes of illness when antibiotics do not improve symptoms. Conclusion: The ChAdOx1-S/nCoV-19 [recombinant] vaccine is a possible trigger of RS3PE. However, the benefits of vaccines against coronavirus outweigh the risks in the majority of patients. LEARNING POINTS: This case demonstrates a possible link between the ChAdOx1-S/nCoV-19 [recombinant] vaccine and autoimmune conditions such as RS3PE.It is important to consider alternative diagnoses when antibiotic regimes fail to work.A barrier to accurate diagnosis includes an episodic approach, where a patient presents to multiple clinicians acutely rather than having a long-term, continuous relationship with a single multi-disciplinary team, where response to treatment can be monitored.

Humoral and T Cell Immune Responses against SARS-CoV-2 after Primary and Homologous or Heterologous Booster Vaccinations and Breakthrough Infection: A Longitudinal Cohort Study in Malaysia.

Vaccine efficacy against SARS-CoV-2 could be compromised by the emergence of SARS-CoV-2 variants and it is important to study how it impacts the booster vaccination regime. We investigated the humoral and T cell responses longitudinally in vaccinated uninfected (n = 25) and post-COVID-19 individuals (n = 8), and those who had received a BNT162b2 booster following complete two-doses regimes of either BNT162b2 (homologous) (n = 14) or ChAdOx1-S (heterologous) (n = 15) vaccines, by means of a SARS-CoV-2 pseudovirus neutralization test and QuantiFERON SARS-CoV-2 assay. Vaccinated post-COVID-19 individuals showed higher neutralizing antibodies with longer durability against SARS-CoV-2 wild type (WT) and Omicron spikes, but demonstrated similar declining T cell responses compared to the uninfected vaccinated. Two doses of BNT162b2 induced higher neutralizing antibodies against WT and T cell responses than ChAdOx1-S for six months. The BNT162b2 booster confers a greater humoral response against WT, but a similar cross-neutralizing antibody against Omicron and T cell responses in the homologous booster group compared to the heterologous booster group. Breakthrough infection in the homologous booster group (n = 11) significantly increased the neutralizing antibody, but T cell responses remained low. Our data may impact government public health policy regarding the administration of mix-and-match vaccines, where both vaccination regimes can be employed should there be shortages of certain vaccines.

Homologous and Heterologous Boosting of the Chadox1-S1-S COVID-19 Vaccine With the SCB-2019 Vaccine Candidate: A Randomized, Controlled, Phase 2 Study.

Background: Ongoing outbreaks of coronavirus disease 2019 (COVID-19) are driven by waning immunity following primary immunizations and emergence of new severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) variants that escape vaccine-induced neutralizing antibodies. It has been suggested that heterologous boosters could enhance and potentially maintain population immunity. Methods: We assessed the immunogenicity and reactogenicity of booster doses of different formulations of aluminium hydroxide-adjuvanted SCB-2019 vaccine (9 µg of SCB-2019, with or without CpG-1018 adjuvant, or 30 µg of SCB-2019 with CpG-1018) in Brazilian adults primed with ChAdOx1-S vector vaccine. S-protein antibodies and ACE2-binding inhibition were measured by enzyme-linked immunosorbent assay (ELISA) on days 1, 15, and 29. Participants self-reported solicited adverse events and reactions. Results: All SCB-2019 formulations increased S-protein ELISA antibodies and ACE2 binding inhibition to a greater extent than ChAdOx1-S. After 30 µg of SCB-2019 + CpG + aluminium hydroxide, titers against wild-type S-protein were significantly higher than after ChAdOx1-S on days 15 and 29, as were titers of neutralizing antibodies against the wild-type strain and Beta, Gamma, Delta, and Omicron variants. Boosting with SCB-2019 or ChAdOx1-S was well tolerated, with no vaccine-related serious or severe adverse events. Conclusions: Boosting ChAdOx1-S-primed adults with SCB-2019 induced higher levels of antibodies against a wild-type strain and SARS-CoV-2 variants than a homologous ChAdOx1-S booster, with the highest responses being with the 30-µg SCB-2019 + CpG + aluminium hydroxide formulation. Clinical Trials Registration: NCT05087368.

ZnO-Based Electrochemical Immunosensor to Assess Vaccine-Induced Antibody-Mediated Immunity against Wild-Type and Gamma SARS-CoV-2 Strains.

The evaluation of serological responses to COVID-19 is crucial for population-level surveillance, developing new vaccines, and evaluating the efficacy of different immunization programs. Research and development of point-of-care test technologies remain essential to improving immunity assessment, especially for SARS-CoV-2 variants that partially evade vaccine-induced immune responses. In this work, an impedimetric biosensor based on the immobilization of the recombinant trimeric wild-type spike protein (S protein) on zinc oxide nanorods (ZnONRs) was employed for serological evaluation. We successfully assessed its applicability using serum samples from spike-based COVID-19 vaccines: ChAdOx1-S (Oxford-AstraZeneca) and BNT162b2 (Pfizer-BioNTech). Overall, the ZnONRs/ spike-modified electrode displayed accurate results for both vaccines, showing excellent potential as a tool for assessing and monitoring seroprevalence in the population. A refined outcome of this technology was achieved when the ZnO immunosensor was functionalized with the S protein from the P.1 linage (Gamma variant). Serological responses against samples from vaccinated individuals were acquired with excellent performance. Following studies based on traditional serological tests, the ZnONRs/spike immunosensor data reveal that ChAdOx1-S vaccinated individuals present significantly less antibody-mediated immunity against the Gamma variant than the BNT162b2 vaccine, highlighting the great potential of this point-of-care technology for evaluating vaccine-induced humoral immunity against different SARS-CoV-2 strains.

A rare case of bilateral optic neuritis post-Covishield (ChAdOx1-S [recombinant]) vaccination.

Multiple adverse effects have been reported in people receiving the COVID-19 vaccinations including few reports of optic neuritis. However, there is no report till date, of bilateral optic neuritis post-ChAdOx1-S (recombinant) vaccination. We report here, for the first time, such a case in a previously healthy woman. Although a direct causal relationship cannot be proven, there was a temporal association between the vaccination and the onset of optic neuritis. Some vaccine adjuvants inciting disproportionate systemic inflammation, molecular mimicry, and the hypercoagulable state seen after COVID-19 vaccination could be the possible causes for the development of optic neuritis. Clinicians should be aware of this adverse effect apart from various other adverse effects of COVID-19 vaccination.

Impact of Improper Storage of ChAdOx1-S (AstraZeneca) Vaccine on Its Efficacy and Safety.

Background: In May 2021, there was an incident regarding giving patients AstraZeneca vaccines stored improperly. They were stored at room temperature (21 degrees centigrade) for 18 h, 12 h longer than the producer recommends. Aim of the study: The paper aims to contribute to the body of knowledge concerning the efficacy and safety of the ChAdOx1-S (AstraZeneca) vaccine concerning the requirements for cold supply chain specification. Patients and methods: Improperly stored vaccines were given to 44 patients, and 39 of them decided to take part in the study. The Control group consisted of 56 people vaccinated on the same days by the same medical teams, using properly stored medicines. Results: The concentration of anti-S1 SARS-CoV-2 Spike protein IgG antibodies did not differ significantly between the groups. Examined group median 70 kU/L (20;100). Control group median 66 kU/L (32.75;100), p = 0.751. We did not observe any COVID-19 infections in either the control or examined group for half a year after the incident. People from each group reported that local and systemic adverse events occurred directly after the first and second doses. In the control group, one case of spontaneously subsiding face edema and joint pain was observed. There were no severe or fatal adverse events. There were no significant differences between the groups, besides the fatigue, after the second dose. Conclusion: AstraZeneca vaccine ChAdOx1-S stored at 21 degrees centigrade for 18 h before vaccination has the same safety profile (p < 0.05) and the same efficacy (p < 0.05) as the vaccines stored in conditions recommended by the producer.

Heterologous prime-boost immunization with ChAdOx1-S and BNT162b2: reactogenicity and immunogenicity in a prospective cohort study.

OBJECTIVES: Regarding reactogenicity and immunogenicity, heterologous COVID-19 vaccination regimens are considered as an alternative to conventional immunization schemes. METHODS: Individuals receiving either heterologous (ChAdOx1-S [AstraZeneca, Cambridge, UK]/BNT162b2 [Pfizer-BioNTech, Mainz, Germany]; n = 306) or homologous (messenger RNA [mRNA]-1273 [Moderna, Cambridge, Massachusetts, USA]; n = 139) vaccination were asked to participate when receiving their second dose. Reactogenicity was assessed after 1 month, immunogenicity after 1, 3, and/or 6 months, including a third dose, through SARS-CoV-2 antispike immunoglobulin G, surrogate virus neutralization test, and a plaque reduction neutralization test against the Delta (B.1.167.2) and Omicron (B.1.1.529; BA.1) variants of concern. RESULTS: The overall reactogenicity was lower after heterologous vaccination. In both cohorts, SARS-CoV-2 antispike immunoglobulin G concentrations waned over time with the heterologous vaccination demonstrating higher neutralizing activity than homologous mRNA vaccination after 3 months to low neutralizing levels in the Delta plaque reduction neutralization test after 6 months. At this point, 3.2% of the heterologous and 11.4% of the homologous cohort yielded low neutralizing activity against Omicron. After a third dose of an mRNA vaccine, ≥99% of vaccinees demonstrated positive neutralizing activity against Delta. Depending on the vaccination scheme and against Omicron, 60% to 87.5% of vaccinees demonstrated positive neutralizing activity. CONCLUSION: ChAdOx1-S/BNT162b2 vaccination demonstrated an acceptable reactogenicity and immunogenicity profile. A third dose of an mRNA vaccine is necessary to maintain neutralizing activity against SARS-CoV-2. However, variants of concern-adapted versions of the vaccines would be desirable.

"Chadox1-S and Bbv152 Vaccines" - Effectiveness on Post-Vaccination and Covid-19 Outcomes

Background: ChAdOx1-S (vaccine A) and BBV152 (vaccine B) vaccines are currently at the forefront of India's fight against the pandemic. The present study tests the hypothesis that both vaccines are equally efficacious. Material(s) and Method(s): This cross-sectional study was conducted at MGM Hospital, Jaipur (Rajasthan, India). The study compared vaccine A and B recipients on post-vaccination events and COVID-19 related outcomes. Researchers collected data using questionnaires circulated through Google Forms. The association between attributes was tested using the chi-squared test. The significance level was considered at 5%. Result(s): The vaccines A and B recipients were age and gender-matched [p > 0.05]. The vaccines did not differ significantly in vaccine events and adverse events after immunization (p > 0.05). A comparison of COVID-19 related outcomes between the two vaccines revealed no significant differences (p > 0.05). However, the severity of symptoms was higher in vaccine B recipients than in vaccine A recipients [p = 0.027] . Conclusion(s): The present study concludes that vaccines A and B were similar in efficacy. The most crucial factor revealed by the survey is that the reporting of adverse events was significantly less, and awareness is needed. Copyright © 2022 Wolters Kluwer Medknow Publications. All rights reserved.

SARS-CoV-2-Specific IgG and IgA response in maternal blood and breastmilk of vaccinated naïve and convalescent lactating participants.

Background: Recent studies have shown the presence of SARS-CoV-2-specific antibodies in the milk of breastfeeding mothers vaccinated with mRNA and convalescent. However, limited information is available in lactating women receiving other vaccine platforms used in developing countries, such as the inactivated SARS-CoV-2 vaccine BBIBP-CorV (Sinopharm) and the non-replicating adenovirus vaccines Sputnik V (Gamaleya Institute) and ChAdOx1-S (Oxford AstraZeneca). Methods: Here, we evaluated anti-SARS-CoV-2 IgG and IgA levels in both serum and milk samples using a longitudinal and a cross-sectional cohort of 208 breastfeeding vaccinated women from Argentina with or without previous SARS-CoV-2 infection. Results: The analysis showed that IgA levels remain constant in serum and milk of breastfeeding mothers between the first and second doses of vector-based vaccines (Sputnik V and ChAdOx1-S). After the second dose, anti-spike IgA was found positive in 100% of the serum samples and in 66% of breastmilk samples. In addition, no significant differences in milk IgA levels were observed in participants receiving BBIBP-CorV, Sputnik V or ChAdOx1-S. IgG levels in milk increased after the second dose of vector-based vaccines. Paired longitudinal samples taken at 45 and 120 days after the second dose showed a decrease in milk IgG levels over time. Study of IgA levels in serum and milk of vaccinated naïve of infection and vaccinated-convalescent breastfeeding participants showed significantly higher levels in vaccinated-convalescent than in participants without previous infection. Conclusion: This study is relevant to understand the protection against SARS-CoV-2 by passive immunity in newborns and children who are not yet eligible to receive vaccination.

Safety and immunogenicity of vaccines against SARS-CoV-2

The mortality rate estimated by the WHO worldwide for CO-VID-19 has been 5.7%, much higher than other communicable infectious diseases, so it is essential to apply a vaccine to the population to reduce the viral spread, according to the WHO there are 23 projects in clinical phase stage III, such as vaccines: ChadOx1, nCov-19, Gam-COVID-Vac, CoronaVac that show promising results in research published by The Lancet Infection Diseases journal, for which we consider correlating the three vaccines and determining which is safer, generates greater im-munogenicity and less reactogenicity in volunteer participants, for which we conducted a review bibliography and a meta-anal-ysis of high impact scientific articles, concluding that the three vaccines generate a rapid and intense immune response against SARS-CoV-2, neutralizing antibodies had elevated titers in participants at 28 days, who increased and remained stable with a second dose, although each of them have been tested in different numbers and populations, applying recombinant adenovi-ral vectors and chemically inactivated virions with adjuvant and placebo for which they are totally different but with the same purpose to generate memory antibodies against SARS-CoV-2. Copyright © 2021, Venezuelan Society of Pharmacology and Clinical and Therapeutic Pharmacology. All rights reserved.

SARS CoV- 2 vaccination induces antibodies against cardiolipin.

OBJECTIVE: Cases of thrombosis have been reported after administration of SARS-CoV-2 vaccines, with controversial results relating to Oxford-AstraZeneca's ChAdOx1-S. Despite such cases being rare, they still raised concerns for their involvement in coagulopathies. Anti-cardiolipin (aCL) IgG antibodies have been linked to venous and arterial thrombosis. The aim was to evaluate the concentration of aCL IgG antibodies in vaccinated and COVID-19 positive individuals using indirect ELISA and commercial sourced calibrators. RESULTS: The concentration of aCL IgG antibodies was measured in the serum of COVID-19 positive (n = 37), ChAdOx1-S vaccinated (n = 37) and BioNTech Pfizer BNT162b2 vaccinated (n = 42) individuals. Samples from COVID-19 negative, unvaccinated individuals (n = 41) served as controls. The highest percentage of positivity was in the COVID-19 positive group (18.9%). Concerning vaccination, BNT162b2 had the highest percentage of positivity (11.9%) (p = 0.0037). Additionally, aCL concentrations were evaluated at different time points in both vaccinated groups (before, 3 weeks after and 3 months after the second dose). A significant difference in the levels of aCL IgG antibodies over time (p = 0.0391) was observed only in ChAdOx1-S individuals. Our study concluded that levels of aCL, after vaccination with either of the vaccines or following SARS-CoV-2 infection, were not clinically pathogenic for the risk of thrombosis.

Population-wide persistent hemostatic changes after vaccination with ChAdOx1-S.

Various vaccines were developed to reduce the spread of the Severe Acute Respiratory Syndrome Cov-2 (SARS-CoV-2) virus. Quickly after the start of vaccination, reports emerged that anti-SARS-CoV-2 vaccines, including ChAdOx1-S, could be associated with an increased risk of thrombosis. We investigated the hemostatic changes after ChAdOx1-S vaccination in 631 health care workers. Blood samples were collected 32 days on average after the second ChAdOx1-S vaccination, to evaluate hemostatic markers such as D-dimer, fibrinogen, α2-macroglobulin, FVIII and thrombin generation. Endothelial function was assessed by measuring Von Willebrand Factor (VWF) and active VWF. IL-6 and IL-10 were measured to study the activation of the immune system. Additionally, SARS-CoV-2 anti-nucleoside and anti-spike protein antibody titers were determined. Prothrombin and fibrinogen levels were significantly reduced after vaccination (-7.5% and -16.9%, p < 0.0001). Significantly more vaccinated subjects were outside the normal range compared to controls for prothrombin (42.1% vs. 26.4%, p = 0.026) and antithrombin (23.9% vs. 3.6%, p = 0.0010). Thrombin generation indicated a more procoagulant profile, characterized by a significantly shortened lag time (-11.3%, p < 0.0001) and time-to-peak (-13.0% and p < 0.0001) and an increased peak height (32.6%, p = 0.0015) in vaccinated subjects compared to unvaccinated controls. Increased VWF (+39.5%, p < 0.0001) and active VWF levels (+24.1 %, p < 0.0001) pointed toward endothelial activation, and IL-10 levels were significantly increased (9.29 pg/mL vs. 2.43 pg/mL, p = 0.032). The persistent increase of IL-10 indicates that the immune system remains active after ChAdOx1-S vaccination. This could trigger a pathophysiological mechanism causing an increased thrombin generation profile and vascular endothelial activation, which could subsequently result in and increased risk of thrombotic events.

Immunogenicity and reactogenicity of heterologous immunization against SARS CoV-2 using Sputnik V, ChAdOx1-S, BBIBP-CorV, Ad5-nCoV, and mRNA-1273.

Heterologous vaccination against coronavirus disease 2019 (COVID-19) provides a rational strategy to rapidly increase vaccination coverage in many regions of the world. Although data regarding messenger RNA (mRNA) and ChAdOx1 vaccine combinations are available, there is limited information about the combination of these platforms with other vaccines widely used in developing countries, such as BBIBP-CorV and Sputnik V. Here, we assess the immunogenicity and reactogenicity of 15 vaccine combinations in 1,314 participants. We evaluate immunoglobulin G (IgG) anti-spike response and virus neutralizing titers and observe that a number of heterologous vaccine combinations are equivalent or superior to homologous schemes. For all cohorts in this study, the highest antibody response is induced by mRNA-1273 as the second dose. No serious adverse events are detected in any of the schedules analyzed. Our observations provide rational support for the use of different vaccine combinations to achieve wide vaccine coverage in the shortest possible time.

Prescrire's ratings of new drugs in 2021: A brief review

Three new drugs, all based on messenger RNA or small interfering RNA technology, represented a major therapeutic advance in 2021. But the bigger picture is that most of the new authorisations that advanced patient care were adaptations of existing drugs. And that more than half of this year's new authorisations were not advances, and in fact about one-tenth represented a step backwards compared to existing options.

MOG encephalomyelitis after vaccination against severe acute respiratory syndrome coronavirus type 2 (SARS-CoV-2): case report and comprehensive review of the literature.

BACKGROUND: In around 20% of cases, myelin oligodendrocyte glycoprotein (MOG) immunoglobulin (IgG)-associated encephalomyelitis (MOG-EM; also termed MOG antibody-associated disease, MOGAD) first occurs in a postinfectious or postvaccinal setting. OBJECTIVE: To report a case of MOG-EM with onset after vaccination with the Pfizer BioNTech COVID-19 mRNA vaccine BNT162b2 (Comirnaty®) and to provide a comprehensive review of the epidemiological, clinical, radiological, electrophysiological and laboratory features as well as treatment outcomes of all published patients with SARS-CoV-2 vaccination-associated new-onset MOG-EM. METHODS: Case report and review of the literature. RESULTS: In our patient, MOG-IgG-positive (serum 1:1000, mainly IgG1 and IgG2; CSF 1:2; MOG-specific antibody index < 4) unilateral optic neuritis (ON) occurred 10 days after booster vaccination with BNT162b2, which had been preceded by two immunizations with the vector-based Oxford AstraZeneca vaccine ChAdOx1-S/ChAdOx1-nCoV-19 (AZD1222). High-dose steroid treatment with oral tapering resulted in complete recovery. Overall, 20 cases of SARS-CoV2 vaccination-associated MOG-EM were analysed (median age at onset 43.5 years, range 28-68; female to male ratio = 1:1.2). All cases occurred in adults and almost all after immunization with ChAdOx1-S/ChAdOx1 nCoV-19 (median interval 13 days, range 7-32), mostly after the first dose. In 70% of patients, more than one CNS region (spinal cord, brainstem, supratentorial brain, optic nerve) was affected at onset, in contrast to a much lower rate in conventional MOG-EM in adults, in which isolated ON is predominant at onset and ADEM-like phenotypes are rare. The cerebrospinal fluid white cell count (WCC) exceeded 100 cells/µl in 5/14 (36%) patients with available data (median peak WCC 58 cells/µl in those with pleocytosis; range 6-720). Severe disease with tetraparesis, paraplegia, functional blindness, brainstem involvement and/or bladder/bowel dysfunction and a high lesion load was common, and treatment escalation with plasma exchange (N = 9) and/or prolonged IVMP therapy was required in 50% of cases. Complete or partial recovery was achieved in the majority of patients, but residual symptoms were significant in some. MOG-IgG remained detectable in 7/7 cases after 3 or 6 months. CONCLUSIONS: MOG-EM with postvaccinal onset was mostly observed after vaccination with ChAdOx1-S/ChAdOx1 nCoV-19. Attack severity was often high at onset. Escalation of immunotherapy was frequently required. MOG-IgG persisted in the long term.

ChAdOx1-S adenoviral vector vaccine applied intranasally elicits superior mucosal immunity compared to the intramuscular route of vaccination.

COVID-19 vaccines prevent severe forms of the disease, but do not warrant complete protection against breakthrough infections. This could be due to suboptimal mucosal immunity at the site of virus entry, given that all currently approved vaccines are administered via the intramuscular route. In this study, we assessed humoral and cellular immune responses in BALB/c mice after intranasal and intramuscular immunization with adenoviral vector ChAdOx1-S expressing full-length Spike protein of SARS-CoV-2. We showed that both routes of vaccination induced a potent IgG antibody response, as well as robust neutralizing capacity, but intranasal vaccination elicited a superior IgA antibody titer in the sera and in the respiratory mucosa. Bronchoalveolar lavage from intranasally immunized mice efficiently neutralized SARS-CoV-2, which has not been the case in intramuscularly immunized group. Moreover, substantially higher percentages of epitope-specific CD8 T cells exhibiting a tissue resident phenotype were found in the lungs of intranasally immunized animals. Finally, both intranasal and intramuscular vaccination with ChAdOx1-S efficiently protected the mice after the challenge with recombinant herpesvirus expressing the Spike protein. Our results demonstrate that intranasal application of adenoviral vector ChAdOx1-S induces superior mucosal immunity and therefore could be a promising strategy for putting the COVID-19 pandemic under control.

Premarket Development Times for Innovative Vaccines--To What Extent Are the Coronavirus Disease 2019 (COVID-19) Vaccines Outliers?

One reason expressed in surveys of people reporting coronavirus disease 2019 (COVID-19) vaccine hesitancy is how rapidly these vaccines have reached the market. To estimate the length of time the COVID-19 vaccine spent in research and development as compared to other novel vaccines, we apply previously established methods for estimating medical product development times, using the key associated patent filings cited by the manufacturer as the marker of when commercial development activity began. Applying these methods to a cohort of recently approved innovative vaccines and comparing them to the first-approved COVID-19 vaccine (BioNTech/Pfizer), we found key patent filings for the technology in this COVID-19 vaccine occurred 10.0 years prior to regulatory authorization. By this metric, the development timelines for innovative vaccines have been shortening since the 1980s, and the COVID-19 vaccine comfortably fits within this pattern. Vaccine development timelines have now even drawn to parity with many of the most commonly used drugs.