Safety and immunogenicity of heterologous boosting with orally aerosolised or intramuscular Ad5-nCoV vaccine and homologous boosting with inactivated vaccines (BBIBP-CorV or CoronaVac) in children and adolescents: a randomised, open-label, parallel-controlled, non-inferiority, single-centre study.

BACKGROUND: Heterologous booster immunisation with orally administered aerosolised Ad5-nCoV vaccine (AAd5) has been shown to be safe and highly immunogenic in adults. Here, we aimed to assess the safety and immunogenicity of heterologous booster immunisation with orally administered AAd5 in children and adolescents aged 6-17 years who had received two doses of inactivated vaccine (BBIBP-CorV or CoronaVac). METHODS: We did a randomised, open-label, parallel-controlled, non-inferiority study to assess the safety and immunogenicity of heterologous booster immunisation with AAd5 (0·1 mL) or intramuscular Ad5-nCoV vaccine (IMAd5; 0·3 mL) and homologous booster immunisation with inactivated vaccine (BBIBP-CorV or CoronaVac; 0·5 mL) in children (aged 6-12 years) and adolescents (aged 13-17 years) who had received two doses of inactivated vaccine at least 3 months earlier in Hunan, China. Children and adolescents who were previously immunised with two-dose BBIBP-CorV or CoronaVac were recruited for eligibility screening at least 3 months after the second dose. A stratified block method was used for randomisation, and participants were stratified by age and randomly assigned (3:1:1) to receive AAd5, IMAd5, or inactivated vaccine. The study staff and participants were not masked to treatment allocation. Laboratory and statistical staff were masked during the study. In this interim analysis, adverse events within 14 days and geometric mean titre (GMT) of serum neutralising antibodies on day 28 after the booster vaccination, based on the per-protocol population, were used as the primary outcomes. The analysis of non-inferiority was based on comparison using a one-sided 97·5% CI with a non-inferiority margin of 0·67. This study was registered at ClinicalTrials.gov, NCT05330871, and is ongoing. FINDINGS: Between April 17 and May 28, 2022, 436 participants were screened and 360 were enrolled: 220 received AAd5, 70 received IMAd5, and 70 received inactivated vaccine. Within 14 days after booster vaccination, vaccine-related adverse reactions were reported: 35 adverse events (in 13 [12%] of 110 children and 22 [20%] of 110 adolescents) in 220 individuals in the AAd5 group, 35 (in 18 [51%] of 35 children and 17 [49%] of 35 adolescents) in 70 individuals in the IMAd5 group, and 13 (in five [14%] of 35 children and eight [23%] of 35 adolescents) in 70 individuals in the inactivated vaccine group. Solicited adverse reactions were also reported: 34 (13 [12%] of 110 children and 21 [10%] of 110 adolescents) in 220 individuals in the AAd5 group, 34 (17 [49%] of 35 children and 17 [49%] of 35 adolescents) in 70 individuals in the IMAd5 group, and 12 (five [14%] of 35 children and seven [20%] of 35 adolescents) in 70 individuals in the inactivated vaccine group. The GMTs of neutralising antibodies against ancestral SARS-CoV-2 Wuhan-Hu-1 (Pango lineage B) in the AAd5 group were significantly higher than the GMTs in the inactivated vaccine group (adjusted GMT ratio 10·2 [95% CI 8·0-13·1]; p<0·0001). INTERPRETATION: Our study shows that a heterologous booster with AAd5 is safe and highly immunogenic against ancestral SARS-CoV-2 Wuhan-Hu-1 in children and adolescents. FUNDING: National Key R&D Program of China.

[Molecular epidemiology investigation of rabies virus nucleoprotein genes in China].

OBJECTIVE: To study the relationship between the distribution of rabies virus and genetic variation, the genetic characterization and variation of rabies virus strains in China were analyzed. METHODS: The downstream 720 nucleotides of Nucleoprotein (N) gene coding region of the rabies specimens from different areas and host animals were sequenced, and then homology and phylogenesis were analyzed. RESULTS: Nucleotide similarities of 34 N gene sequences were 87.5%-100%, and the deduced amino acid similarities were 93.3%-99.6%. Most of the nucleotide variations were synonymous mutations. CONCLUSION: The 34 rabies specimens all belong to genotype I and are of regional characteristic. The rabies viruses in high-incidence areas in China are of various origins and present the transmission tendency from high-incidence areas to surrounding regions. There may be cross-infection and mutual spread of rabies virus between wildlife and domestic animals as well as native and foreign animals.

[Survey and anslysis of infection rate of dog rabies in the regions with high incidence of human rabies].

OBJECTIVE: To investigate the situation of dog rabies and analyze it's relationship with human rabies. METHODS: In Guizhou, Guangxi and Hunan provinces which suffered from rabies most heavily, one or two cities were selected respectively from regions with high-, middle-, low-incidence rate of human rabies as investigation spots where Dogs' brain specimens were collected and detected with both direct immunofluorescence assay (IFA) and RT-PCR. RESULTS: A total of 2887 specimens were collected and 66 of these were positive for IFA and RT-PCR. Therefore, the rate of positive specimens was 2.3%. However, there was not a close relationship in the incidence rate of dog rabies and human rabies. CONCLUSION: Dog's infection situation of rabies contributed to the severe epidemic of human rabies.

[Characterization of rabies virus phosphoprotein in high prevalence provinces of China].

OBJECTIVE: Characterization of rabies virus phosphoprotein through analyzation of genetic variations about rabies virus phosphoproteins in high-incidence regions in China. METHODS: The nucleotide sequence of the P gene of Guangxi, Guizhou and Hunan provinces positive sample's were sequenced, and the P region's similarity and phylogenetic analyses were completed by using softer wares. RESULTS: The similarity of P region's nucleotide sequence is 82.1%-100%, while, the similarity of amino acid sequence is 87.5%-100%. A little variation in phosphoprotein cannot influence its biological functions. CONCLUSION: All rabies viruses isolated from Guangxi, Guizhou and Hunan provinces belong to genotype 1 and share same phylogenesis and same genome characteristic; Virus distribution presents unique Characterization; Some virus isolates from Hunan province and Thailand may come from the same virus.

[Genetic characterization of Chinese rubella virus isolates from 2003 to 2007].

57 rubella virus strains were isolated using Vero cell line or Vero/SLAM cell line from patients' throat swabs during rubella outbreaks and sporadics in 10 provinces of China from 2003 to 2007. Fragments of 1107 nucleotides of E1 genes of the isolates were amplified by RT-PCR, the PCR products were directly sequenced and analyzed. The phylogenetic analysis based on 739 nucleotides showed that out of 57 Chinese rubella virus strains, 55 belong to a distinguish branch of 1E genotype when comparing with 1E genotype rubella strains from other countries, and the other 2 Chinese rubella virus strains belong to 2B genotype. Most of the nucleotide mutations of 57 rubella viruses were silent mutations, and the amino acid sequences were highly conserved. Except one amino acid change (Thr212 --> Ser212) in two rubella viruses at the hemagglutination inhibition and neutralization epitopes, there had no change found at the important antigenic epitope sites of the other rubella viruses. 1E genotype rubella viruses isolated from 10 provinces of China from 2003 to 2007, and two imported 2B genotype rubella viruses from Vietnam suggested that 1E genotype was the predominant genotype in this period of time. The rubella virus genotypes circulated during 2003 to 2007 were different from that circulating during 1979 to 1984 and 1999 to 2002, the rubella prevailed in recent years was mainly caused by 1E genotype rubella viruses with multi-transmission routes.

[Viral surveillance on rabies in Hunan province, in 2006].

OBJECTIVE: To understand the source and distribution of rabies virus (RV) in Hunan province with viral surveillance in order to provide scientific measures for prevention and control on rabies. METHODS: Brain samples from healthy-looking domestic dogs were collected in the agricultural markets at the districts of high, middle, and low incidence rates and detected by direct Immunofluorescence assay (DFA). Positive samples would be further detected by RT-PCR and the surveillance samples were detected by RT-PCR. The positive samples detected by RT-PCR were sequenced with N gene. RESULTS: The infection rate of those healthy-looking domestic dogs with rabies virus was 2.78% in Hunan province in 2005. 23 positive samples' N gene were sequenced and their similarities were 88.8% - 100.0%. The results indicated that Hunan rabies virus N gene aberrance was mainly synonymous aberrance and did not carry obvious regional characteristics. The rabies virus were circulating among different districts in Hunan province, and the neighboring provinces such as Guizhou, Hubei, Guangxi, Jiangsu and Henan. There were no positive samples detected in salivary, blood and urine samples. There was one positive sample detected in two skin samples. CONCLUSION: There are dogs infected with rabies virus found in Hunan province and this study showed that rabies virus detected in Hunan had a close genetic relationship with those rabies identified in other provinces, suggesting that study on the immunity and management of dog related rabies should be strengthened.

[An epidemiologle investigation of hantaviruses carried by rodent hosts in Hunan province].

OBJECTIVE: To explore the hantavirus infection and their genotype in rodents in Hunan. METHODS: Hantavirus antigens in the rat lungs from Hunan province were detected by immunofluorescence assay. Partial S and M segment in antigen-positive samples were amplified by RT-PCR, and then sequenced. The phyologenetic trees were constructed for the analysis of genetic characters of hantavirus. RESULTS: A total of 344 rats were trapped in the main epidemic area of Hunan province, and hantavirus antigens were found in 6 of the 344 rats( 1.74% ).The phylogenetic trees constructed by partial S segment( nt 620-990) or partial G2 segment (nt 2001- 2301) showed that the hantaviruses carried by Rattus norvegicus, R . flabipectus and R. rattoides from Xiangxiang district were genetic subtype SEOV4. The virus carried by R. norvegicus in Ningyuan district was phylogenetically different from the known SEOV. The hantavirus carried by Mus musculus from Shimen district was genetic subtype HTNV4. CONCLUSION: The hantaviruses in the main epidemic areas in Hunan province mainly belonged to SEOV, and R. flabipectus and R. rattoides carried the same genotype of SEOV as R. norvegicus.

[Virological surveillance on hemorrhagic fever with renal syndrome in Hunan province in 2006].

OBJECTIVE: To understand the rate of viral carrying status among rodents as well as genotypes and distribution of Hantaviruses (HV) isolated in Hunan province. METHODS: With DFA, the HV antigen in lung tissues of rodents was detected. The total viral RNA was extracted from the lung tissues of the HV infected rats and amplified with reverse transcrition-polymerase chain reaction (RT-PCR), using the HV genotype specific primers. The amplified genes were then sequenced and subjected to genotyping and homologic analysis. RESULTS: The average density of rodents was 3.15% and the virus carrying rate among rodents was 1.31%. Data from genotype analysis showed that the HV isolated from seven lung specimens taken from Rattus norvgicus, Apodemus agraius, Mus musculus, Rattus flavipectus among indoor rodents in Shaodong and Liuyang belonged to HV type II (SEOV), and one isolated from Apodemus agraius in Shaungfen belonged to HV type I (HTNV) among outdoor rodents. Six strains were sequenced successfully and the homology between six srains was 88.3%-100%. The homology of HN1, HN2, HN4, HN6 came from Liuyang and the HN7 and HN8 from Shaodong were both 100% while the homology between L99 and the strains from Liuyang and Shaodong were 94.4% and 88.3% respectively. CONCLUSION: HV type II (SEOV) and the HV type I (HTNV) were all existed in Hunan province while SEOV was the main genotype.