People who have recovered from COVID-19 and gained immunity to the disease could lose it again within months, a new study from the UK suggests. According to the research by a team from King’s College London, the novel coronavirus (SARS-CoV-2) could reinfect people year after year, much like common colds. Having studied the immune responses of more than 90 patients and healthcare workers at Guy’s and St Thomas’ NHS foundation trust, the researchers found that COVID-19 antibody levels peaked about three weeks after the onset of symptoms. [Related reading: Coronavirus: Immunity levels likely to be higher than antibody tests suggest] Blood tests revealed that while 60% of COVID-19 patients displayed a “potent” antibody response at the height of their battle with the disease, this figure fell to just 17% three months later. In some cases, antibody levels became undetectable. The findings of the study have implications when it comes to developing a COVID-19 vaccine, as well as achieving greater herd immunity. The bottom line is that if antibody levels drop over time and people are able to be reinfected seasonally, a vaccine would not actually provide any long-term benefits. Speaking about the findings of the study, Dr Katie Doores, lead author from King’s College London, said: “People are producing a reasonable antibody response to the virus, but it’s waning over a short period of time and depending on how high your peak is, that determines how long the antibodies are staying around.”
More people have immunity to coronavirus than antibody tests suggest, new research shows. The study from Sweden found that for every person who tested positive for antibodies — which are usually a strong indicator of whether someone has previously had an infection — two were found to have specific T-cells which identify and destroy infected cells. According to the research from the Karolinksa Institute in Sweden, even individuals who had mild or asymptomatic cases of COVID-19 had T-cells, despite testing negative for antibodies. The research is important because it could mean that more people than first thought have immunity to COVID-19. However, it is not yet clear whether this just protects the individual, or if it also stops them from passing on the infection to others. Prof Danny Altmann at Imperial College London described the study as “robust, impressive and thorough" and said it added to a growing body of evidence that "antibody testing alone underestimates immunity”. The results of the study are so new that they have not undergone peer review, nor been published in a scientific journal. Nevertheless, they can be seen as good news from a public health perspective as they indicate that public immunity to COVID-19 is likely a lot higher than first thought.
Children in Italy have been told not to go to school unless they can prove they have been properly vaccinated. Any children under six who cannot show that they have received mandatory vaccines will be turned away from school, while parents of older kids (six to 16) risk being fined up to €500 ($566) if they send their unvaccinated children to school. The policy comes as a worrisome decline in vaccines has been seen across Italy and a measles outbreak was witnessed last year. Speaking about the new policy, Health Minister Giulia Grillo said the rules were now simple: “No vaccine, no school.” She added that parents have had adequate time to ensure all their children’s vaccines were up to date by now. Under Italy’s so-called Lorenzin law, children must receive a range of mandatory immunizations before attending school. These include vaccinations for chickenpox, polio, measles, mumps, and rubella. Italian officials say the compulsory vaccine law has led to inoculation rates for measles reaching the 95% population coverage rate recommended by the World Health Organization (WHO) – the threshold for “herd immunity.” The deadline by which children had to be vaccinated was March 10 (after a previous delay). And despite calls for it to be extended, the Health Minister has stood firm on the issue.