Chinese researchers have claimed that a potential coronavirus vaccine developed by the CanSino Biologics appeared safe and triggered an immune response. Earlier this week, Massachusetts-based Moderna announced preliminary Phase I data that shows both safety and efficacy for its mRNA vaccine.
The Lancet estimates that around 100 potential active substances are in development worldwide, including in the United Kingdom where a huge vaccine test of over 10,000 people will begin soon. Most adverse events were mild or moderate, with 83% (30/36) of those receiving low and middle doses of the vaccine and 75% (27/36) in the high dose group reporting at least one adverse reaction within 7 days of vaccination.
"We showed that vaccines induce antibodies, and the vaccinated animals are protected either partially or fully", Dr Barouch said, CBS reported.
The first phase of the recombinant adenovirus type-5 (Ad5) vectored COVID-19 vaccine was carried out at several laboratories by the researchers and included 108 participants between the age of 18 to 60 years.
It's not yet clear whether the shot - if it proves effective - will be available in the USA, and the Department of Health and Human Services had not responded to request for comment at the time of publication. Further studies will be needed to confirm whether the vaccine protects against infection.
The researchers tested the volunteers" blood at regular intervals following vaccination to see whether the vaccine stimulated both arms of the immune system: the body's "humoral response' (the part of the immune system that produces neutralising antibodies which can fight infection and could offer a level of immunity), and the body's cell-mediated arm (which depends on a group of T cells, rather than antibodies, to fight the virus).
Researchers in China did find that people who had Ad5 antibodies were less likely to develop a strong immune response to the vaccine. After 28 days, most participants had a significant increase in binding antibodies.
After two weeks, the vaccine produced virus-fighting antibodies across all dose levels, with the highest dose level triggering antibodies in 61 percent of those who took it. Data the company released was limited to a handful of trial participants, so at this point it is largely unknown how effective that vaccine candidate could be, but the company was optimistic.
'The one thing not we're not seeing is a really high neutralizing antibody titer, ' he told DailyMail.com.
More studies will be needed to determine whether the vaccine can protect against infection in practice.
Encouragingly, none of the 108 patients had serious side effects. The most common adverse reactions were fever, fatigue, headache and muscle pain.
A Reuters poll published Thursday found that a quarter of Americans were not very or not at all interested in getting a vaccine for the virus that has infected more than 1.6 million people in the US. It is not only a problem of manufacturing the vaccine itself with the same degree of quality, after having the vaccine it is necessary to have millions of needles, syringes, tons of cotton, to guarantee that the distribution chains manage to keep the vaccine always in the necessary conditions - of temperature, for example - and to make everything reach each population, prioritizing the most vulnerable people - such as medical personnel, elderly people and people with aggravating medical conditions such as diabetes or heart failure.
So far, the USA government is supporting the development of 14 candidate vaccinations through its Operation Speed initiative. The final results will be evaluated in six months.