(CNN)The United States is giving older adults the option of getting a second Covid-19 vaccine booster dose as studies suggest the fourth jab offers stronger protection.
US joins club of nations offering second booster
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Some moderately or severely immunocompromised people who had had three doses of the Pfizer/BioNTech or Moderna Covid-19 vaccines were already able to get a fourth dose of vaccine. The US Food and Drug Administration (FDA) extended that coverage to adults who are age 50 and older yesterday, Brenda Goodman reports.
"Current evidence suggests some waning of protection over time against serious outcomes from Covid-19 in older and immunocompromised individuals. Based on an analysis of emerging data, a second booster dose of either the Pfizer-BioNTech or Moderna COVID-19 vaccine could help increase protection levels for these higher-risk individuals," said Dr. Peter Marks, director of the FDA's Center for Biologics Evaluation and Research, in a news release.
There was "solid data from Israel" to back the rollout, Dr. Eric Topol, a cardiologist who is director of the Scripps Research Translational Institute in California, told CNN in an email.
In December, Israel became the first country to give fourth shots to those over the age of 60 and the immunocompromised, and research shows "enhanced protection (versus severe illness) out to three months compared" with people who only have one booster shot, Topol wrote, adding: "It is reasonable to extend that and provide it as an option, since the 3rd dose has pronounced benefit in age 50+."
The United Kingdom also offers a second booster to adults over the age of 75, people in care home settings and those with weakened immune systems. Before an expected rise in cases ahead of next winter, an independent expert committee that advises the UK's health departments on immunizations has indicated that a fifth dose of the vaccine should be given to vulnerable age groups in the fall.
Not everyone is behind the decision to roll out a fourth jab in the US. Experts say a second booster may be warranted for people at higher risk of severe illness, including older adults. However, the usefulness of an additional dose for younger people at lower risk is less clear and is not as widely endorsed.
Dr. Paul Offit, director of the vaccine education center at the Children's Hospital of Philadelphia, who is a member of a group of independent experts who advise the FDA on its vaccine decisions, felt the administration was acting ahead of the science. "Where's the evidence that somebody over 50 benefits from a fourth dose? Because the evidence to date appears to support the possibility for those over 65, although I haven't, we haven't, seen all the data," Offit told CNN, speaking of the Vaccines and Related Biological Products Advisory Committee members. "Absent that evidence, then there shouldn't be this recommendation," he said.
After opposing the widespread use of additional jabs because of concern about the global vaccine supply, the World Health Organization's vaccine advisory group came out in support of booster doses earlier in March. This shift came amid reports that WHO'S vaccine sharing program, COVAX, has a glut in vaccine supplies -- exacerbated by gaps in infrastructure and equipment to distribute the jabs in low-income countries, Reuters reports.
Q: Which vaccine gives the best protection against breakthrough infections?
A: A recent CNN analysis of data from the US Centers for Disease Control and Prevention (CDC) showed the Johnson & Johnson vaccine had the lowest breakthrough infection rate during a five-week span starting in late December -- the latest five weeks of available data.
In January, during the Omicron surge in the US, breakthrough infections were highest among those who received the Pfizer/BioNTech vaccine, followed by people who got the Moderna vaccine. Those vaccinated with the Johnson & Johnson shot had the lowest incidence of breakthrough infections.
But any vaccine is better than no vaccine at all. During the Delta and Omicron surges, unvaccinated people were more than twice as likely to get infected compared with those who got Pfizer or Moderna shots. And the odds of getting Covid-19 were more than three times higher for unvaccinated people compared with those who had the Johnson & Johnson vaccine.
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Studies link Covid-19 infection with increased risk of new diabetes diagnosis
Experts have known that people with diabetes are at higher risk of severe Covid-19 infection, but now, a new connection is appearing -- one in which a Covid-19 infection may lead to a higher risk of diabetes, Tasnim Ahmed reports.
One study published this month looked at people who had mild Covid-19 infections in Germany and found that they were 28% more likely to have a new diagnosis of type 2 diabetes compared with people who were never infected.
A study in the United States similarly found an increased incidence of diabetes in people who had recovered from Covid-19 -- a 40% increase in risk at least a year after infection. The researchers estimate that about two out of every 100 people who are infected with Covid-19 will have a new diagnosis of diabetes.
This US-based study, published last week in the medical journal The Lancet, also found that even among people who had low to no risk factors for diabetes, Covid-19 infection led to a 38% increased risk of diabetes afterward.
Biden administration to offer Covid-19 vaccines to migrants
The Biden administration will offer Covid-19 vaccines to migrants taken into custody at the US-Mexico border, according to two sources familiar with the planning, and confirmed by the Department of Homeland Security, as officials prepare for an influx of migrants, Priscilla Alvarez writes.
The plan could extend to thousands of migrants encountered at the US' southern border. The Department of Homeland Security will initially be able to provide up to 2,700 vaccine doses a day, it said in a notice to Congress obtained by CNN, increasing to 6,000 daily by the end of May.
Offering the Covid-19 vaccine to migrants at the US' southern border would be an extension of what the Biden administration is already doing for migrants subject to the Trump-era "remain in Mexico" policy. Last year, top White House officials rejected a proposal to vaccinate migrants, because they thought it would encourage more people to come to the US, sources told CNN. Now, the administration is moving ahead with the plan.
Shanghai forces residents into a two-phase lockdown
On Monday, Shanghai began its two-phase lockdown, which saw the eastern half of the city close at 5 a.m. local time for four days of mass testing, with the western half to follow on Friday. The lockdown comes as Shanghai emerged as the new epicenter of China's worst outbreak of Covid-19 in two years, reporting a record 3,500 cases on Sunday.
During the lockdowns, people will be banned from going out, and all non-essential workers must work from home. Public transportation including buses, subways, ferries and taxis in lockdown areas will also be suspended, as the ruling Communist Party pursues a "zero-Covid" policy to stamp out all infections, Simone McCarthy reports.
But China's inability to bring its latest outbreak under control so far has prompted online rumblings from frustrated citizens, as questions about the zero-Covid strategy break into the mainstream for the first time. Some Chinese citizens now appear to think the health measures are more onerous than the illness itself.
As Covid-19 cases fall and masks come off, flu cases rise
After being nearly non-existent last year, influenza is increasing in most of the US. In 2021, it saw very little flu -- most likely because of the measures people took to combat Covid-19: wearing masks, limiting gatherings, trying to move things outside, where respiratory viruses spread less easily.
The CDC estimates that, as of Friday, there have been at least 3.1 million infections, 31,000 hospitalizations and 1,800 deaths from flu so far this season.
For some of us, even the smallest interactions can feel daunting. CNN's Chief Medical Correspondent, Dr. Sanjay Gupta, investigates what's really going on in our brains when we experience social anxiety. Plus, hear usable tips for how we all can sharpen our social skills after several years of pandemic life. Listen here.