The Latest on COVID-19: Will Vaccines be Available Soon?
Because deaths lag cases and hospitalizations by at least three weeks, we can expect the daily death rate to climb substantially in the coming months. Some are predicting over 3,000 dead per day by late December. Interventions to slow infections such as wearing masks, limiting indoor public encounters at bars, restaurants and gyms, limiting the number of people attending mass gatherings such as worship services, funerals and parties, are being initiated. It will take several weeks for such interventions to have an effect on infection rates. The pandemic is going to get a lot worse before the rate of daily new infections starts to decline.
That’s extremely troubling for prisoners and their families because prisons and jails have a higher rate of infection and death than the general U.S. population, largely due to overcrowding and an inability to social distance and obtain adequate personal protective equipment. In addition, many prisoners have underlying health conditions making them more vulnerable.
More About Masks
The reason to wear a mask is to reduce the amount of infectious droplets the person wearing the mask releases into the air. An infected person releases tiny infectious droplets during breathing, talking and singing. Larger droplets with much larger numbers of infectious virus are released during shouting, sneezing and coughing. The mask partially blocks release of these infectious droplets into the air.
A mask definitely helps protect other people from getting infected when the person wearing the mask is already infected. Since we don’t know who is infected, everyone should wear a mask in public.
There is still some debate whether the person wearing the mask is partially protected from infectious droplets already present in the air. Some recent studies say yes it does; others suggest no, not really. It may turn out that masks block the larger droplets that contain much larger numbers of infectious viruses. There also is some evidence that the more viruses invading during the initial infection, the worse the disease. So, masks may help prevent these larger numbers that can cause more severe disease.
The quality of the mask matters. A well-fitted N-95 mask blocks virus entry well. A disposable surgical mask works too, but not as well as an N-95. Cloth masks may be even less effective. Masks made of cloth that is thinly woven with large gaps between threads are easier to wear and breath through but may not be useful at all. A face shield worn without a mask is not very useful either as it blocks neither outgoing infectious droplets nor incoming droplets.
Vaccines Nearing Approval
As of November, two vaccines were close to emergency approval for public use in the U.S. The vaccines are developed by coalitions of companies, but named for the large drug manufacturers that are involved, Pfizer and Moderna.
Antibodies are made by the body’s immune system to fight infections. Antigens are molecules on the germs that antibodies attach onto to disable them. The purpose of a vaccine is to stimulate the body to make antibodies specific to the germ that will prevent it from initiating an infection. Vaccines usually target an antigen on the surface of the germ. The pandemic coronavirus has spikes on its surface that help it attach to human cells and inject its RNA into the cell to make more viruses. Many of the vaccines being developed target a protein antigen on the spikes. Vaccine trials are necessary to determine if the vaccine is safe, if antibodies are produced, and whether or not those antibodies actually prevent infection in people who have been vaccinated.
Both the Pfizer and Moderna vaccines have been shown to be safe, to stimulate production of antibodies, and to prevent infection at about a 95% level. They have also been shown to be effective in older people as well as healthy young people. This is all very good news.
At more than $30 per dose, these vaccines are expensive to produce because they use a relatively new technology. Instead of injecting spike protein antigen itself to stimulate antibodies, these vaccines inject messenger RNA (mRNA) that is used by the virus to make spike protein. Then the immune system makes antibodies to the spike protein. This technology has not been used much in the past to make vaccines so there is little experience with this type of vaccine.
The mRNA is not stable at room temperature for very long so the vaccine has to be kept frozen during distribution and storage. If it thaws too soon, it won’t be effective.
The Pfizer vaccine has to be kept at about minus 100 degrees and is only stable in a refrigerator for five days. This is a huge problem for Pfizer vaccine distribution because there are very few freezers that can achieve minus 100 degrees, even in the U.S.
The Moderna vaccine is stable at normal freezer temperatures and is stable in a refrigerator for 30 days. This one will be much easier to distribute but is still at risk for loss of potency if thawed too soon. Some commonly used vaccines require freezing until used (chickenpox vaccine for children for example) and there are substantial losses every year due to inadvertent thawing from power failures and leaky freezer doors.
There are other candidate vaccines being developed that use actual spike protein, not mRNA. They will be cheaper at around $1 per dose. It will not be necessary to keep them frozen. The technology to produce them is well known and widespread. It is likely that less developed countries will be able to make their own vaccines of this type. These are the vaccines that will stop the pandemic worldwide when they become available.
Nasal Spray to Prevent Infection
Coronavirus infects people mostly through the cells that line the nose, throat and lungs. A drug that blocked infection in these sites would be a dramatic improvement in prevention. Researchers at Columbia University and colleagues elsewhere have found a molecule that may block infection when sprayed up the nose once a day. It attaches to the spikes on the virus and prevents it from injecting its genetic material into the cell to take over and make more viruses. The spray has only been tested in animals so far, but it’s very promising. It is safe, cheap, easy to produce, stable at room temperature, and does not require an injection. You would just spray it up your nose at home once a day to prevent infection. This information is based on early, small animal studies. Human studies will likely be initiated soon.
One of the big issues with testing has been the time delay between the test and the results. The better-quality tests that look for virus RNA take one to two days to process at best. Longer delays have been common recently. More rapid tests have become available that look for virus antigens. These were approved for emergency use to test people with symptoms, but have come to be widely used for mass testing of people without symptoms, too. For example, the White House used rapid antigen tests to screen people before they met with the president.
Recent studies of the accuracy of the rapid tests have been completed and the results are not good. Rapid antigen tests were compared to results from better quality viral RNA tests. For people with symptoms, the rapid test was positive for 80% of the people who were positive on the standard viral RNA test. That isn’t perfect, but most of the true positives were identified by the rapid test. However, for people without symptoms the rapid test only found 34% of the true positives found by viral RNA tests. The rapid tests are not reliable when used to screen people without symptoms.
One of the proposed treatments for COVID-19 has been to use antibodies to the virus. People who recovered from COVID-19 have donated blood so their antibodies could be extracted and used to treat sick people. Antibody treatments has been used for more than a century with good results prior to the development of effective antibiotics. President Trump received antibody treatment when he was sick with COVID-19.
The results of new studies of the effectiveness of antibody treatment have been made available. Antibodies were given to severely ill hospitalized patients. They did not do any better than the severely ill hospitalized patients who did not receive antibody treatment. So, this treatment for the severely ill in the hospital failed. Other studies may show better effects in less severely ill patients.
The good news about vaccines nearing approval is not going to end the pandemic any time soon. After approval, to have any effect on the course of the pandemic, vaccines have to be produced in huge numbers, distributed, and administered to people. Vaccines are a step. Vaccinated people are what is needed to make a difference.
Meanwhile, the pandemic is worse than ever and people are dying in ever-higher numbers. The measures we have available right now—wearing masks, limiting indoor exposure to people you don’t live with, limiting mass gatherings, and staying farther apart when you are with other people are the tools we have to make a difference right now.