Moderna vaccine ‘can be tweaked to work against variants’, according to trials

Test trials have shown positive promising results against foreign variants.

Vaccines that have been "tweaked" to help combat worrying Covid-19 variants form South Africa and Brazil have successfully neutralised them in laboratory trials. The news from US vaccine maker and pharmaceutical company Moderna suggests that booster jabs will be feasible this year to help combat new variants of the virus. Some of these are feared to be more transmissible or vaccine-resistant. Other companies such as Pfizer/BioNTech and Oxford/AstraZeneca have been racing to develop similar tweaked vaccines as well. Moderna are the first to announce results though, and they appear to be positive, although only limited and basic information from an initial analysis of results is available so far. The Guardian reports that the trials for booster shots of the vaccine and tweaked doses of the vaccine for those that have already had two doses involved 40 adults, 20 for each arm of the trial. Two weeks after being given the new jab, Moderna say that both the booster shot and the altered vaccine increased the antibodies in the blood of participants that can neutralise the two variants of concern: the South African variant (B1351) and the Brazilian variant (P1). However, the tweaked vaccine that is designed to combat the two variants produced higher levels of neutralising antibodies than the standard booster jab. Moderna is also running a trial in which participants are given a mixture of the booster jab and the tweaked jab. The company's CEO Stéphane Bancel said: "As we seek to defeat the ongoing pandemic, we remain committed to being proactive as the virus evolves. We are encouraged by these new data, which reinforce our confidence that our booster strategy should be protective against these newly detected variants.

"Our mRNA platform allows for rapid design of vaccine candidates that incorporate key virus mutations, potentially allowing for faster development of future alternative variant-matched vaccines should they be needed … We will continue to make as many updates to our Covid-19 vaccine as necessary to control the pandemic."

Moderna reported that there were few side-effects from the vaccines and those that were reported were mild. Apart from pain at the injection site, the most common reported side-effects were fatigue, headache, muscle pain and joint pain.