Coronavirus Resource Center – Harvard Health

Coping with coronavirus:

The news about coronavirus and its impact on our day-to-day lives has been unrelenting. There’s reason for concern and it makes good sense to take the pandemic seriously. But it’s not good for your mind or your body to be on high alert all the time. Doing so will wear you down emotionally and physically.

Click here to read more about coping with coronavirus.

New questions and answers

When can I discontinue my self-quarantine?

A full, 14-day quarantine remains the best way to ensure that you don’t spread the virus to others after you’ve been exposed to someone with COVID-19. However, according to CDC guidelines, you may discontinue quarantine after a minimum of 10 days if you do not have any symptoms, or after a minimum of 7 days if you have a negative COVID test within 48 hours of when you plan to end quarantine.

Who will get the first COVID-19 vaccines?

Healthcare workers and residents and staff of long-term care facilities will get the first COVID-19 vaccines once the vaccines are granted Emergency Use Authorization (EUA).

There are about 21 million healthcare workers in the US, doing a variety of jobs in hospitals and outpatient clinics, pharmacies, emergency medical services, and public health. Another three million people reside or work in long-term care facilities, which include nursing homes, assisted-living facilities, and residential care facilities. COVID-19 has taken a heavy toll on residents of long-term care facilities.

Both Pfizer/BioNTech and Moderna have applied to the FDA for EUA of their vaccines. Pfizer’s vaccine is expected to receive EUA in mid-December, and Moderna’s vaccine soon after. Both of these vaccines require two doses spaced a few weeks apart. The companies estimate that they will have enough to vaccinate about 20 million people by the end of December, with vaccine production continuing to ramp up in early 2021. Other vaccines, including one by AstraZeneca, are also on the horizon.

The next priority groups for vaccination are expected to include essential workers, adults with underlying medical conditions that increase risk for severe COVID-19, and adults over age 65.

The CDC’s guidance is based on a recommendation from the Advisory Committee on Immunization Practices (ACIP), made up of experts in vaccinology, immunology, virology, public health, and other related fields. Their work is not limited to the COVID-19 vaccine; they broadly advise the CDC on vaccinations and immunization schedules.

What are adenovirus vaccines? What do we know about adenovirus vaccines that are being developed for COVID-19?

Adenoviruses can cause a variety of illnesses, including the common cold. They are being used in two leading COVID-19 vaccine candidates as capsules (the scientific term is vectors) to deliver the coronavirus spike protein into the body. The spike protein prompts the immune system to produce antibodies against it, preparing the body to attack the SARS-CoV-2 virus if it later infects the body.

In a press release, AstraZeneca announced promising preliminary results of an adenovirus-based vaccine that it developed with researchers at the University of Oxford.

The preliminary analysis was based on more than 23,000 adult study participants enrolled in a phase 3 clinical trial. Of these, nearly 9,000 participants received a full dose of the coronavirus vaccine, followed four weeks later by another full dose. Nearly 3,000 participants received a half dose of the coronavirus vaccine, followed four weeks later by a full dose. The control group received a meningitis vaccine, followed by a second meningitis vaccine or a placebo (a saltwater shot). There were 131 documented cases of COVID-19, all of which occurred at least two weeks after the second shot.

The coronavirus vaccine reduced the risk of COVID-19 by an average of 70.4%, compared to the control group. Surprisingly, the half dose/full dose vaccine combination was more effective, reducing risk of COVID-19 by 90%. The full dose combination reduced risk by 62%. None of the participants who received the coronavirus vaccine developed severe COVID-19 or had to be hospitalized. There was also a reduction in asymptomatic cases.

All study participants were healthy or had stable underlying medical conditions. This vaccine is in clinical trials around the world, including the US. But this analysis was based on data from the United Kingdom and Brazil.

The adenovirus used in the AstraZeneca/University of Oxford vaccine is a weakened, harmless form of a chimpanzee common-cold adenovirus. This vaccine can be safely refrigerated for several months.

What are monoclonal antibodies? Can they help treat COVID-19?

The FDA has granted emergency use authorization (EUA) to two new treatments for COVID-19. Both are monoclonal antibodies. And both have been approved to treat non-hospitalized adults and children over age 12 with mild to moderate symptoms who have recently tested positive for COVID-19, and who are at risk for developing severe COVID-19 or being hospitalized for it. This includes people over 65, people with obesity, and those with certain chronic medical conditions.

The FDA granted EUA to the first treatment, a monoclonal antibody called bamlanivimab made by Eli Lilly, based on an interim analysis of results from a well-designed but small clinical trial. The study looked at 465 non-hospitalized adults with mild to moderate COVID-19 symptoms who were at high risk of severe disease. A placebo was given to 156 of these patients. The remaining patients were given one of three different doses of bamlanivimab. Patients treated with the monoclonal antibody had a reduced risk (3% versus 10%) of being hospitalized or visiting the ER within 28 days after treatment, compared to patients given a placebo. This is a single-dose treatment that must be given intravenously and within 10 days of developing symptoms.

The FDA has also granted EUA to a combination therapy consisting of two monoclonal antibodies, casirivimab and imdevimab, made by Regeneron. The EUA was based on results from a clinical trial that enrolled 799 non-hospitalized adults with mild to moderate COVID-19 symptoms. The participants were divided into three groups, two of which received the casirivimab-imdevimab combination but at different doses. The third group received a placebo. For patients at high risk for severe disease, those treated with the monoclonal antibody treatment had a reduced risk (3% versus 9%) of being hospitalized or visiting the ER within 28 days of treatment. This treatment must also be given intravenously in a clinic or hospital.

Monoclonal antibodies are manmade versions of the antibodies that our bodies naturally make to fight invaders, such as the SARS-CoV-2 virus. Both of these FDA-approved therapies attack the coronavirus’s spike protein, making it more difficult for the virus to attach to and enter human cells.

These treatments are not authorized for hospitalized COVID-19 patients or those receiving oxygen therapy. They have not shown to benefit these patients and could lead to worse outcomes in these patients.

Is there an at-home diagnostic test for COVID-19?

The FDA has approved the first diagnostic test for COVID-19 that can be completed entirely at home, from sample collection to receiving the results. Other FDA-approved COVID-19 tests allow at-home sample collection, but still have to be shipped to a laboratory for processing.

The Lucira COVID-19 All-In-One Test Kit is approved for people ages 14 and older who are suspected of having COVID-19. It requires a doctor’s prescription. The company does not expect the test to be widely available until the spring of 2021.

To perform the test, you swirl a swab in both nostrils, then stir the swab in a vial of chemicals. The vial is then plugged into a battery-powered test unit, which returns a positive or negative test result within 30 minutes.

The test works by making copies of the virus’s genetic material (if present) until it reaches detectable levels. It does this using a technique called loop-mediated isothermal amplification (LAMP). The method is similar to PCR, the gold standard of COVID-19 diagnostic testing. The LAMP test provides much faster results, but it is less accurate. In a head-to-head comparison, the Lucira test missed 6% of people who tested positive for COVID by PCR.

Because a person can be infected and have a negative LAMP test, you should always self-quarantine if you have symptoms consistent with COVID, or have had recent contact with someone who has the infection, until you can get a PCR test.

What are mRNA vaccines? What do we know about mRNA vaccines that are being developed for COVID-19?

mRNA, or messenger RNA, is genetic material that contains instructions for making proteins. mRNA vaccines for COVID-19 contain synthetic mRNA. Inside the body, the mRNA enters human cells and instructs them to produce the “spike” protein found on the surface of SARS-CoV-2, the virus that causes COVID-19. The body recognizes the spike protein as an invader, and produces antibodies against it. If the antibodies later encounter the actual virus, they are ready to recognize and destroy it before it causes illness.

In the past couple of weeks, two companies have released promising data about their mRNA vaccines. Results for both vaccines were reported in company press releases, not in peer reviewed scientific journals.

One of the mRNA vaccines was developed by Pfizer and BioNTech. Their phase 3 clinical trial found that their vaccine reduced the risk of infection by 95%. The trial enrolled nearly 44,000 adults. Of these, half received the vaccine and half got a placebo (a shot of saltwater). Of the 170 cases of COVID-19 that developed in the study participants, 162 were in the placebo group and eight were in the vaccine group. Nine of the 10 severe COVID cases occurred in the placebo group. This suggests that the vaccine reduces risk of both mild and severe COVID. The vaccine was consistently effective across age, race, and ethnicity. Of the US study participants, 30% were people of color and 45% were age 56 to 85.

The other mRNA vaccine, developed by Moderna, released an interim analysis of its phase 3 trial, announcing that its vaccine was 94.5% effective. This study enrolled 30,000 adults; half received the vaccine, half received a saltwater placebo shot. There were 95 infections among the study participants. Of these, 90 were in the placebo group and 5 were in the vaccine group. All 11 severe COVID cases occurred in the placebo group. This vaccine also appears to reduce risk of mild and severe illness. And it was effective in older people, people with medical conditions that put them at high risk for severe illness, and in racial and ethnic minorities, which made up 37% of the study participants. The study enrolled more than 7,000 participants older than 65, and more than 5,000 people under 65 who were at high risk for severe illness.

Both vaccines had a good safety record. Side effects included fatigue, headache, and muscle pain.

These results are promising, but there are still questions left to be answered. For example, we do not yet know how long immunity from these vaccines will last. Both of these vaccines require two doses (three weeks between shots for the Pfizer vaccine and four weeks between shots for the Moderna vaccine), and we don’t know how effective the vaccine is in people who only get one dose. There is also the question of storage. mRNA vaccines must be stored at very cold temperatures, and improperly stored vaccines can become inactive.

Do pregnant women face increased risks from COVID-19?

A large study from the CDC has found that pregnant women are at increased risk of severe COVID-19 illness compared to women who are not pregnant.

The study looked at 409,462 women, ages 15 to 44, who had symptomatic COVID-19. Of these women, 23,434 were pregnant. Even after taking age, race, ethnicity, and underlying health conditions into consideration, pregnant women were significantly more likely to need intensive care, to require a ventilator, and to require a heart-lung bypass machine, compared to women who were not pregnant. They were also 70% more likely to die.

It’s important to note that the overall risk of these complications was low. For example, 1.5 symptomatic pregnant women out of 1,000 died, compared to 1.2 symptomatic women out of 1,000 who were not pregnant.

The CDC also released a smaller study, which found that women who were infected with the COVID-19 virus during pregnancy were more likely to deliver preterm (earlier than 37 weeks).

If you are pregnant, be vigilant about taking precautions. Wear a mask, physically distance from others, and avoid social gatherings. Do your best to follow the CDC’s recommendations to protect yourself if someone in your household becomes infected.

Continue to see your doctor for prenatal visits and get any recommended vaccines. Call your doctor’s office to discuss safety precautions if you have concerns.

Could wearing masks prevent COVID deaths?

According to a new study published in the journal Nature Medicine, widespread use of masks could prevent nearly 130,000 of 500,000 COVID-related deaths estimated to occur by March 2021.

These numbers are based on an epidemiological model. The researchers considered, state by state, the number of people susceptible to coronavirus infection, how many get exposed, how many then become infected (and infectious), and how many recover. They then modeled various scenarios, including mask wearing, assuming that social distancing mandates would go into effect once the number of deaths exceeded 8 per 1 million people.

Modeling studies are based on assumptions, so the exact numbers are less important than the comparisons of different scenarios. In this study, a scenario in which 95% of people always wore masks in public resulted in many fewer deaths compared to a scenario in which only 49% of people (the self-reported national average of mask wearers) always wore masks in public.

This study reinforces the message that we can help prevent COVID deaths by wearing masks.

What does the CDC’s new definition of “close contacts” mean for me?

The CDC has expanded how it defines close contacts of someone with COVID-19. Until this point, the CDC had defined a close contact as someone who spent 15 or more consecutive minutes within six feet of someone with COVID-19. According to the new definition, a close contact is someone who spends 15 minutes or more within six feet of a person with COVID-19 over a period of 24 hours.

Close contacts are at increased risk of infection. When a person tests positive for COVID-19, contact tracers may identify their close contacts and urge them to quarantine to prevent further spread. Based on the new definition, more people will now be considered close contacts.

Many factors can affect the chances that infection will spread from one person to another. These factors include whether or one or both people are wearing masks, whether the infected person is coughing or showing other symptoms, and whether the encounter occurred indoors or outdoors. Though the “15 minutes within six feet rule” is a helpful guideline, it’s always best to minimize close interactions with people who are not members of your household.

The CDC’s new definition was influenced by a case described in the CDC’s Morbidity and Mortality Weekly Report in which a correctional officer in Vermont is believed to have been infected after being within six feet for 17 non-consecutive minutes of six asymptomatic individuals, all of whom later tested positive for COVID-19.

How does obesity increase risk of COVID-19?

According to a recent review and meta-analysis that looked at 75 international studies on the subject, obesity is a significant risk factor for illness and death due to COVID-19.

When looking at people with COVID-19, the analysis found that, compared with people who were normal weight or overweight, people who were obese were

Obesity may impact COVID risk in several ways. For example, obesity increases the risk of impaired immune function and chronic inflammation, both of which could make it harder for the body to fight the COVID-19 infection. Excess fat can also make it harder for a person to take a deep breath, an important consideration for an illness that impairs lung function.

People who are obese are also more likely to have diabetes and high blood pressure, which are themselves risk factors for severe COVID-19. And obesity is more common in Black, Latinx, and Native Americas, who are more likely to get infected and die from COVID-19 than whites for a variety of reasons.

If you have obesity (defined as a body mass index, or BMI, of 30 or higher), stay vigilant about protecting yourself from infection. That means maintaining physical distance, avoiding crowds when possible, wearing masks, and washing your hands often.