Virus World

Chikungunya virus (CHIKV) is a reemerging mosquito-borne virus that causes swift outbreaks. Major concerns are the persistent and disabling polyarthralgia in infected individuals. Here we present the results from a first-in-human trial of the candidate simian adenovirus vectored vaccine ChAdOx1 Chik, expressing the CHIKV full-length structural polyprotein (Capsid, E3, E2, 6k and E1). 24 adult healthy volunteers aged 18–50 years, were recruited in a dose escalation, open-label, nonrandomized and uncontrolled phase 1 trial (registry NCT03590392). Participants received a single intramuscular injection of ChAdOx1 Chik at one of the three preestablished dosages and were followed-up for 6 months. The primary objective was to assess safety and tolerability of ChAdOx1 Chik.

The secondary objective was to assess the humoral and cellular immunogenicity. ChAdOx1 Chik was safe at all doses tested with no serious adverse reactions reported. The vast majority of solicited adverse events were mild or moderate, and self-limiting in nature. A single dose induced IgG and T-cell responses against the CHIKV structural antigens. Broadly neutralizing antibodies against the four CHIKV lineages were found in all participants and as early as 2 weeks after vaccination. In summary, ChAdOx1 Chik showed excellent safety, tolerability and 100% PRNT50 seroconversion after a single dose. Chikungunya virus (CHIKV) is a reemerging mosquito-borne virus that has caused outbreaks in various regions of the world. Here the authors present safety and immunogenicity data from a phase 1 trial with the simian adenovirus vectored vaccine ChAdOx1 Chik, showing induction of neutralizing antibodies to four CHIKV lineages.

Published in Nat. Communications (July 30, 2021):

https://doi.org/10.1038/s41467-021-24906-y

Experimental COVID-19 vaccine also triggers lower adverse responses among older people, British drug maker AstraZeneca said, raising hopes in the fight against the coronavirus pandemic. The vaccine, developed by the University of Oxford, also triggers lower adverse responses among the elderly, AstraZeneca, which is helping manufacture the vaccine, said on Monday. This could potentially be seen as a game-changer in the battle against the novel coronavirus, which has infected more than 43 million people worldwide, killed at least 1.15 million people, shuttered swathes of the global economy, and turned normal life upside down for billions of people. “It is encouraging to see immunogenicity responses were similar between older and younger adults and that reactogenicity was lower in older adults, where the COVID-19 disease severity is higher,” an AstraZeneca spokesman said. “The results further build the body of evidence for the safety and immunogenicity of AZD1222,” the spokesman said, referring to the technical name of the vaccine. 

AstraZeneca did not provide details of the data behind the statement or say when it would publish eagerly awaited late-stage phase-three trial data, which would show whether the vaccine works well enough in large-scale trials for it to be approved. The Oxford/AstraZeneca vaccine is expected to be one of the first from big pharma to secure regulatory approval, along with Pfizer and BioNTech’s candidate, as the world tries to plot a path out of the COVID-19 pandemic. The news that older people get an immune response from the vaccine is positive because the immune system weakens with age and older people are those most at risk of dying from the coronavirus. British Health Secretary Matt Hancock said a vaccine was not yet ready, but he was preparing logistics for a possible roll-out mostly in the first half of 2021.  Asked if some people could receive a vaccine this year, he told the BBC: “I don’t rule that out but that is not my central expectation. “The programme is progressing well [but] we’re not there yet,” Hancock said.