With a highly contagious delta coronavirus This option is spreading at an alarming rate, with the World Health Organization urging people to wear masks indoors again in late June 2021 – even those who are fully vaccinated.
And on July 15, Los Angeles County, California, announced that it would again require camouflage in public enclosed spaces, regardless of vaccination status. This was followed by a recommendation – albeit not a decree – from the seven Gulf counties for everyone to wear masks again in public areas.
It is noteworthy that the US Centers for Disease Control and Prevention has not yet taken a similar position.
On July 12, National Nurses United, the nation’s largest professional association of registered nurses, urged the CDC to reconsider its decision in light of the surge in new infections and hospitalizations across the country.
The Conversation asked Peter Chin-Hong, an infectious disease physician at the University of California, San Francisco, to help understand the science behind these seemingly mixed messages.
What is the science behind the WHO recommendation?
There is clear and growing evidence that, although rare, breakthrough COVID-19 infections can occur even in fully vaccinated individuals. This is especially true for emerging options of concern.
The CDC is monitoring this data closely. By mid-July 2021, nearly 60 percent of the US population aged 18 and over had been fully vaccinated.
Infections in those who are fully vaccinated are rare, and serious outcomes from COVID-19 in this population are even rarer, although they still occur. However, the CDC has stopped tracking out-of-hospital cases of COVID-19 among fully vaccinated people with and without symptoms as of May 1, 2021.
However, the risk of infection resulting in serious illness and death varies sharply between vaccinated and unvaccinated people.
Are breakthrough infections more likely with the delta variant?
May be. Preliminary evidence suggests that an increase in the number of variants, such as delta, may increase the likelihood of breakthrough infections in people who receive only the first dose of the vaccine. For example, one peer-reviewed study found that a single dose of Pfizer vaccine was only 34% effective against the delta variant versus 51% against the older alpha variant in terms of preventing symptomatic disease. …
But the data is more encouraging for those who have received the full vaccination. Based on real life data from Scotland and several other countries, after two doses, Pfizer vaccine still provides reliable protection against the delta variant; and in preliminary studies in Canada and England, researchers noted only a “moderate” decrease in efficacy against symptomatic diseases, from 93% for the alpha variant to 88% for the delta variant.
However, a recent preliminary report from Israel is sobering. Before the delta variant became widespread, Israel reported from January to April 2021 that the Pfizer vaccine was 97 percent effective in preventing symptomatic diseases. However, since June 6, when the delta variant circulated more widely, the Pfizer vaccine has been 64 percent more effective at preventing symptomatic disease, according to preliminary data released by the Israeli Ministry of Health in early July.
In another new report, which has not yet been peer-reviewed, researchers compared antibodies in the serum of people vaccinated with Pfizer, Moderna, and J&J vaccines and found that the J&J vaccine provided much lower protection against delta, beta, and other variants compared to with mRNA. vaccine based.
As a result, the researchers speculate that J&J vaccine recipients would benefit from booster immunizations, ideally with one of the mRNA vaccines. However, this is a limited laboratory study that does not consider whether real people got sick and contradicts a peer-reviewed study that showed the J&J vaccine protected against delta eight months after vaccination.
However, in all the reports and studies, the vaccine’s efficacy compared to the delta variant is still very high in preventing hospitalizations and serious illness – perhaps the results we are most concerned about.
All of this new evidence supports the WHO recommendation that even fully vaccinated people continue to wear masks.
Most countries around the world still have low vaccination rates, a range of vaccines are used with varying efficacy to prevent infection, and there is a varying burden of circulating SARS-CoV-2 virus. In this context, it makes sense that WHO would make a conservative masking recommendation for everyone.
Who is actually protected by the camouflage guidelines?
The WHO’s latest call for fully vaccinated people to continue wearing masks is primarily intended to protect the unvaccinated, including children under 12 who are not yet eligible for vaccination in the United States. Unvaccinated people are at a significantly higher risk of infection and transmission. SARS-CoV-2 and developing complications of COVID-19.
Again, the risk of infection in vaccinated people is still low, but this risk differs from region to region. In areas with high viral circulation and low vaccination rates, as well as high transmission options, vaccinated individuals are more likely to become infected than people living in areas with lower levels of the virus in the community.
Does the situation in the US justify the disguise (again)?
I suspect the CDC is unlikely to comply with the universal US recommendation to wear masks at this time. With an overall high vaccination rate across the country and a low total number of COVID-19 hospitalizations and deaths in the United States, the COVID-19 situation is very different from most other countries in the world.
Some experts are also concerned that the official announcement that vaccinated people must wear masks could discourage unvaccinated people from getting vaccinated.
What changes will signal that the US should hide again? There are emotional red flags, and then there are more realistic red flags that could spark a nationwide call to camouflage themselves indoors for fully vaccinated people.
More than 100 cases per 100,000 people per week are defined by the CDC as “high” transmission in the community, the worst category. Los Angeles County, for example, has already surpassed that mark, with more than 10,000 coronavirus cases per week.
A more pragmatic indicator of camouflage is the number of hospitalizations, as it is directly related to the use of health resources. Some researchers have suggested a threshold of five COVID-19 cases – on average over several days – hospitalized per 100,000 people, which could potentially be a more ominous signal than infection rates. Los Angeles County has surpassed this as well.
Horse racing is likely to be a regional phenomenon, depending on how many people are fully vaccinated in a given area. As long as hospitalizations and deaths remain generally nationally manageable and hospital capacity is maintained, the United States as a whole may not need to return to camouflage in a fully immunized facility.