ABSTRACT
Objective:To analyze the molecular epidemiological characteristics of measles virus (MV) in Beijing from 2015 to 2019, and to provide laboratory basis for measles elimination.Methods:Measles virus-positive throat swab samples were collected through the Beijing Measles Laboratory network from 2015 to 2019. After the viral nucleic acid was extracted, 450 nucleotide fragments of the C terminal of the N gene of MV were amplified by RT-PCR. Nucleotide sequencing was performed for the amplified products. The phylogenetic tree was constructed with the representative strains of WHO measles virus genotype D8 genotype reference strains in China and other countries. Genotype identification was conducted and the nucleotide and amino acid homology analysis was carried out. A descriptive analysis of measles cases with D8 and B3 genotypes was conducted.Results:From 2015 to 2019, the genotypes of 546 MV were identified in the city, including 531 of H1a genotype, five vaccine strains, one of B3 genotype, and nine of D8 genotype, among which eight were epidemic strains in 2019. The homology of indigenous H1a genotype MV nucleotide and amino acid was 91.5%-100.0% and 73.6%-100.0%.In 2019, all eight cases of D8 genotype measles were adults, with two being an outbreak and the remaining six sporadic cases.Conclusions:The imported D8 genotype had become the main MV genotype in Beijing in 2019. With the decrease of measles incidence in 2019, native genotype H1a was no longer dominant, while other different genotypes were imported, forming a mixed epidemic trend. It was suggested that in the elimination of measles in Beijing, efforts should be made not only to block the transmission of local measles virus, but also to prevent and control the import and continuous transmission of non-local genotype virus, so as to avoid the risk of establishing local transmission by gradually evolving into a dominant strain.
ABSTRACT
<p><b>OBJECTIVE</b>To compare the safety of haemophilus influenzae type b (Hib) vaccine vaccination on vastus lateralis muscle and deltoid muscle of infant.</p><p><b>METHODS</b>A total of 408 3-4 months old infants were divided into vastus lateralis muscle group and deltoid muscle group in Beijing, 2014. They were divided into the vastus lateralis muscle group (204) and deltoid muscle group (204) by extracting random number. Each observation object was given 3 doses of Hib vaccine according to the program. Collected systemic and local reactions after vaccination and calculated the incidence of adverse reactions.</p><p><b>RESULTS</b>A total of 61 infants were quitted during the study, 1 132 doses were observed. The total reactions incidence of Vastus lateralis muscle group and Deltoid muscle group were 33.0% (186/564) and 27.6% (157/568) with no statistical differences (χ² = 3.818, P = 0.059). The two groups incidence at the same day of vaccination (day 0) which the highest were 23.2% (131/564) and 20.6% (117/568), then declined with time (linear trend test vastus lateralis muscle group χ² = 36.600, P < 0.001,deltoid muscle group χ² = 29.947, P < 0.001), day 1 were 20.4% (115/564) and 17.6% (100/568), day 2 were 16.0% (90/564) and 13.4% (76/568), day 3 were 10.3% (58/564) and 10.6% (60/568), day 4-7 were 11.2% (63/564) and 11.3% (64/568). No serious adverse events (SAE) were reported during the study. The local reactions incidence of two groups were 7.1% (40/564) and 7.7% (44/568)with no statistical differences (χ² = 0.176, P = 0.675). The systemic reactions incidence of two groups were 25.9% (146/564) and 20.6% (117/568) with obvious statistical differences (χ² = 4.437, P = 0.035). The fever incidence of vastus lateralis muscle group (11.5% (65/564)) was higher than Deltoid muscle group (4.4% (25/568)) with obvious statistical differences (χ² = 4.868, P = 0.027). The 1st dose incidence of fever and abnormal crying of vastus lateralis muscle group (fever 11.3% (23/204), abnormal crying 19.1% (39/204)) was higher than deltoid muscle group (fever 4.4% (9/204), abnormal crying 11.8% (24/204)) and the 2nd dose of diarrhea of deltoid muscle group (11.6% (22/190)) was higher than vastus lateralis muscle group (5.9% (11/187)) with obvious statistical differences (fever χ² = 15.288, P < 0.001, abnormal crying χ² = 4.224, P = 0.040, diarrhea χ² = 3.829, P = 0.046).</p><p><b>CONCLUSION</b>Both vastus lateralis muscle group and deltoid muscle group had lower incidence of adverse reactions after vaccination. No serious adverse events were associated with vaccination. Vastus lateralis muscle vaccination as well as deltoid muscle vaccination demonstrated safe.</p>