China’s Sinovac COVID-19 vaccine safe for kids
Phase 1/2 clinical trials of China’s CoronaVac vaccine found that two doses were safe and triggered a strong antibody response in young people between 3–17 years old.
CoronaVac, developed by Beijing-based company Sinovac, is one of two front-running COVID-19 vaccines to come out of China. It is an inactivated vaccine, meaning it uses killed viral particles to expose the immune system to SARS-CoV-2.
In this randomised controlled trial, the results of which are published in The Lancet Infectious Diseases, more than 96% of young people vaccinated developed antibodies against the virus. A quarter of participants experienced adverse reactions, though most of these were mild to moderate including pain at the injection site.
T cell responses were not assessed, and the study only involved a relatively small number of participants (550), all of Han ethnicity.
“Further studies in other regions, involving larger, multi-ethnic populations, could provide valuable data to inform immunisation strategies involving children and adolescents,” says Qiang Gao, of Sinovac Life Sciences Co, Ltd, China.
The ethics of vaccine incentives
In the US, people have been offered discounts, prizes, gift cards, sports tickets, lottery tickets and even free beer as incentives to get their COVID-19 jab. But are these benefits ethical and useful?
According to an opinion piece published in JAMA, yes they are.
“While benefit programs that recognise or encourage [peoples’] choice to be vaccinated may not always be the right approach, and may not be a sustainable approach, they are neither fundamentally ethically objectionable nor ethically unique,” write the authors, Govind Persad from the University of Denver, Colorado, and Ezekiel J. Emanuel from the University of Pennsylvania, Philadelphia.
They argue that incentives or even just cash payments are able to offset the financial concerns of individuals.
“Costs, such as time off work for getting a vaccine or dealing with vaccine-related adverse effects, finding daycare for children, and transportation to a vaccine site, hamper access for poorer and marginalised people,” they write.
Since getting vaccinated will protect both the individual and the wider community, they argue that offering benefits is neither coercion or exploitation, as some have suggested.
“Others have a more fundamental objection: that medical decisions should be made without reference to an individual’s financial interests,” Persad and Emanuel acknowledge. “Financial benefits, however, could help to focus vaccine decisions on medical factors by offsetting other costs.”
Lockdowns are more effective in rich countries
A study in PLOS One has found large variability in the effectiveness of COVID-19 restrictions, but with more developed countries typically faring better from lockdowns.
The researchers, based at the University of Western Australia and BRAC University in Bangladesh, analysed the effect of COVID-19 restrictions on both mobility and case numbers in 131 countries.
While lockdown restrictions halted mobility far more in underdeveloped countries, they also were less effective at preventing spread of COVID-19. The authors believe this could be due to lower levels of awareness, poorer overall health conditions, and worse economic conditions.
“It would seem less-developed countries with weaker institutions have less to gain from stricter mobility restrictions,” write the authors in their paper.
One jab might be enough if you’ve already had COVID – for now
A team of US researchers have found that people who have already had COVID-19 can generate enough antibodies to protect themselves after one dose of an mRNA vaccine – but boosters will be important for everyone as time goes on.
The researchers analysed the antibodies of 36 participants who’d had either mild or severe COVID. After the first dose of a Pfizer or Moderna vaccine, the participants had a very strong antibody response, but little happened after their second dose.
They also examined 28 participants who hadn’t had COVID. In both groups of people, antibody levels dropped off after a second dose, indicating that booster shots may be required in coming months.
The research is published in ACS Nano.
Real-world data gives mRNA vaccines a stamp of 91% effectiveness
A paper published in The New England Journal of Medicine has looked at the effectiveness of mRNA vaccines in 3,975 frontline workers, showing them to be highly effective.
The researchers, who are based at the US Centers for Disease Control and Prevention, tracked these workers from December 2020 to April 2021, testing them weekly for SARS-CoV-2.
Of the 172 workers who tested positive over the period, 5 had been fully vaccinated against COVID-19, while 11 were partially vaccinated and 156 were unvaccinated.
Adjusting for demographic factors, the authors calculated that the mRNA vaccines were 91% effective at preventing disease.