Virus World

Even mild SARS-CoV-2 infections can amplify a person’s chance of developing diabetes, especially for those already susceptible to the disease.  People who get COVID-19 have a greater risk of developing diabetes up to a year later, even after a mild SARS-CoV-2 infection, compared with those who never had the disease, a massive study1 of almost 200,000 people shows. The research, published in The Lancet Diabetes & Endocrinology earlier this month, is one of a growing number of studies2 showing that COVID-19 can increase a person’s risk of diabetes, months after infection. “When this whole pandemic recedes, we’re going to be left with the legacy of this pandemic — a legacy of chronic disease” for which health-care systems are unprepared, says study co-author Ziyad Al-Aly, chief researcher for the Veterans Affairs (VA) St Louis Healthcare System in Missouri.

Risks amplified

Al-Aly and Yan Xie, an epidemiologist also at the VA St Louis Healthcare System, looked at the medical records of more than 180,000 people who had survived for longer than a month after catching COVID-19. They compared these with records from two groups, each of which comprised around four million people without SARS-CoV-2 infection who had used the VA health-care system, either before or during the pandemic. The pair previously used a similar method to show that COVID-19 increases the risk of kidney disease3, heart failure and stroke4. The latest analysis found that people who had had COVID-19 were about 40% more likely to develop diabetes up to a year later than were veterans in the control groups. That meant that for every 1,000 people studied in each group, roughly 13 more individuals in the COVID-19 group were diagnosed with diabetes. Almost all cases detected were type 2 diabetes, in which the body becomes resistant to or doesn’t produce enough insulin. The chance of developing diabetes rose with increasing severity of COVID-19. People who were hospitalized or admitted to intensive care had roughly triple the risk compared with control individuals who did not have COVID-19. Even people who had mild infections and no previous risk factors for diabetes had increased odds of developing the chronic condition, says Al-Aly. Of the people with COVID-19 who avoided hospitalization, an extra 8 people out of every 1,000 studied had developed diabetes a year later compared with people who were not infected. People with a high body-mass index, a measure of obesity — and a considerable risk factor for type 2 diabetes — had more than double the risk of developing diabetes after a SARS-CoV-2 infection.

Global burden

Given the extraordinary number of COVID-19 cases globally — 480 million confirmed cases and counting — the modest increase in diabetes risk could correspond to a drastic rise in the number of people diagnosed with the disease worldwide, if the observed trends hold true, says Jonathan Shaw, an epidemiologist at the Baker Heart and Diabetes Institute in Melbourne, Australia. But the findings might not translate to other groups of people. The US veterans in the study were mostly older, white men, many of whom had elevated blood pressure and were overweight, putting them at high risk of developing diabetes, says Gideon Meyerowitz-Katz, an epidemiologist studying diabetes at the University of Wollongong in Australia. But that risk is much lower in younger people, he says, and higher in some other ethnic groups. And it’s possible that some people in the control group had undetected mild or asymptomatic COVID-19 but were never tested, potentially skewing the data, Al-Aly adds. Other factors might also be contributing to the apparent rise in diabetes among people who recovered from COVID-19, says Shaw. Existing cases of diabetes might have gone undetected until people sought medical care for COVID-19.

Elusive causes

Early in the pandemic, researchers raised concerns based on anecdotal reports in young people and children that SARS-CoV-2, like other viruses, might damage cells in the pancreas that produce insulin, triggering type 1 diabetes. But data on a link between SARS-CoV-2 infection and newly diagnosed cases of type 1 diabetes remain mixed. Several studies5–7 have found no evidence that the disease is causing the uptick in cases of type 1 diabetes in younger adults or children. And a laboratory study published in February also challenged the idea that SARS-COV-2 destroys insulin-producing pancreatic cells8. A lingering question is whether the metabolic changes observed in people who had COVID-19 persist after one year. More research is needed to clarify long-term trends in new-onset diabetes at a population level and to tease apart what might be causing them, says Shaw.

Research cited published in The Lancet Diabetes and Endocrinology (March 21, 2022):

https://doi.org/10.1016/S2213-8587(22)00044-4

Two new pieces of research add strong evidence to the case for giving just a single dose of the Pfizer vaccine to people who have antibodies against the virus.  For people who have had Covid-19, a single dose of the Pfizer vaccine is enough to provide robust protection from the coronavirus, according to two newstudies from Britain that were published late Thursday in The Lancet, a prominent medical journal. The studies, among the first fully vetted papers to weigh in on how to vaccinate people who have had Covid-19, added strong evidence to the case for inoculating people who already have antibodies against the virus — but only with one dose of the Pfizer vaccine. One of the studies, led by researchers at University College London and Public Health England, described the benefits of that strategy. “This could potentially accelerate vaccine rollout,” they said. And that in turn could forestall dangerous new mutations: “Wider coverage without compromising vaccine-induced immunity could help reduce variant emergence,” the paper said. In recent weeks, several studies on the topic were posted online that were not yet published in scientific journals, showing that one dose of a coronavirus vaccine amplified people’s antibodies from an earlier infection.

People’s immune responses to being infected are highly variable: Most people make considerable and long-lasting antibodies, while others who had milder infections produce relatively few, making it difficult to know how protected they are from the virus. Vaccines act as a sort of booster for those people’s immune responses, inducing enough antibodies to offer protection. But a single dose, rather than the full two-dose protocol, is enough for those who have been infected, a number of studies have suggested.  Some researchers in the United States are trying to persuade the Centers for Disease Control and Prevention to recommend giving only one dose to people who have recovered from Covid-19. The studies from Britain seem likely to put pressure on health officials there to consider the same approach. More than 28 million people in the United States and four million people in Britain, along with many others whose illnesses were probably never diagnosed, have been infected so far. One of the new studies — led by Charlotte Manisty, a professor at University College London, and Ashley D. Otter, a research scientist at Public Health England — tracked 51 health workers in London who have submitted to routine tests for antibodies and infection since March. That gave researchers an unusually detailed picture of any pre-existing protection from the virus.

During the first wave of the COVID-19 pandemic, fewer than 10% of the US adult population formed antibodies against SARS-CoV-2, and fewer than 10% of those with antibodie swere diagnosed. Public health efforts to limit SARS-CoV-2 spread need to especially
target racial and ethnic minority and densely populated communities. Many patients receiving dialysis in the USA share the socioeconomic characteristics of underserved communities, and undergo routine monthly laboratory testing, facilitating a practical, unbiased, and repeatable assessment of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) seroprevalence.

"Current evidence does not, therefore, appear to show a need for boosting in the general population, in which efficacy against severe disease remains high," the scientists write in a new opinion piece, published Monday in the medical journal The Lancet.  The authors of the paper include two senior FDA vaccine leaders, Dr. Philip Krause and Marion Gruber, who will be stepping down in October and November, the FDA announced late last month. No further details were released about their retirements, although they sparked questions about whether the departures would affect the agency's work. The FDA and other public health agencies around the world continue to examine evidence on Covid-19 vaccine efficacy and the role booster doses of vaccine might play in improving immunity against the disease.  For the new paper in The Lancet, the scientists note that they reviewed randomized trials and observational studies on Covid-19 vaccines and consistently find that "vaccine efficacy is substantially greater against severe disease than against any infection; in addition, vaccination appears to be substantially protective against severe disease from all the main viral variants. Although the efficacy of most vaccines against symptomatic disease is somewhat less for the delta variant than for the alpha variant, there is still high vaccine efficacy against both symptomatic and severe disease due to the delta variant." The scientists note that there is an opportunity right now to study variant-based boosters before there could be a widespread need for them. But they also argue in their paper that the current Covid-19 vaccine supply could "save more lives" if used in people who are not yet vaccinated than if used as boosters. In early August, the World Health Organization called for a moratorium on booster shots until at least the end of September.

A peer-reviewed article in The Lancet shows the vaccine has an impressive 91.6 percent efficacy rate against the virus and is completely protective against severe cases of Covid-19.  MOSCOW — Russia cleared a hurdle in its vaccine rollout on Monday with the publication in the respected British medical journal The Lancet of late-stage trial results showing that the country’s Sputnik V vaccine is safe and highly effective. The publication is sure to buoy the Russian government’s promotion of the vaccine at home and around the world, strengthening the Kremlin’s hand in vaccine diplomacy with a credible endorsement of the product’s safety. Russia drew criticism from Western experts when it approved the vaccine for emergency use in August — before late-stage trials had even begun — and started vaccinations that month. Moscow claimed victory in the vaccine race, as it had decades earlier in the space race with the launch of the Sputnik satellite, though at the time other vaccines were further along in testing. In the end, its politicized rollout only served to deepen skepticism.