COVID-19 Update New Developments, New Opportunities and Challenges in 2022

COVID-19 Update:

New Developments, New Opportunities and Challenges in 2022

by Debra Powell, MD Chief, Division of Infectious Diseases Medical Director, Infection Prevention Tower Health

WHERE ARE WE NOW?

We have now passed the second anniversary of the start of the COVID-19 pandemic. The SARS-CoV-2 virus has affected us all. Many have been infected, suffered the loss of family members, incurred financial hardships, and were not able to participate in significant in-person life events. The good news is that the community case numbers have greatly improved from the peak of the Omicron variant in mid-January 2022 and the requirements for mask use have decreased or been eliminated. Our community is very relieved to be getting back to normal interactions.

WHAT HAVE WE LEARNED AND WHAT TREATMENTS ARE AVAILABLE?

We have learned a great deal about treating and preventing this infection and are very fortunate that we have effective oral and intravenous medications for treating COVID-19 infection plus highly effective vaccines to prevent severe infection requiring hospitalization and contributing to decreasing deaths.

Our antiviral medications include two oral medications: ritonavir-boosted nirmatrelvir (Paxlovid) and molnupiravir; plus, IV remdesivir. Both ritonavir-boosted nirmatrelvir and molnupiravir medications received Emergency Use Authorization (EUA) by the FDA for treating COVID-19 in an outpatient setting for those with mild-to-moderate disease who are at high risk of progressing to severe disease and/or hospitalization. Both medications have significant precautions that must be considered prior to prescribing. Remdesivir is being used for high-risk hospitalized patients. All antiviral medications are most effective when used in the first 5- 7 days of the disease course.

Ritonavir-booster nirmatrelvir, due to the ritonavir component, has severe drug-drug interactions with many medications that must be cross referenced prior to prescribing. The dose must be adjusted for renal insufficiency and cannot be prescribed for patients with severe renal or liver dysfunction.

Molnupirivir induces errors in the virus genetic code that prevents the virus from further replicating. Molnupirivir is not recommend for use during pregnancy due to embryo-fetal toxicity and is not authorized for patients less than 18 years of age due to bone and cartilage toxicity. Females of childbearing potential should use a reliable method of contraception correctly and consistently for the duration of treatment and for 4 days after the last dose of molnupiravir. Males of reproductive potential who are sexually active with females of childbearing potential should use a reliable method of contraception correctly and consistently during treatment and for at least 3 months after the last dose.

In their clinical trials, hospitalization and death in those patients at highest risk were reduced by 88% for ritonavir-boosted nirmatrelvir compared to 30% for molnupiravir.

For high-risk patients we also have monoclonal antibody intravenous treatments that have shown to decrease progression to severe disease requiring hospitalization and death. Due to the changing circulating variants, we have shifted the preferred product based on the variant for better efficacy. Our current preferred monoclonal antibody is sotrovimab which is effective against the initial Omicron variant. We also have a small supply of bebtelovimab which will provide an additional monoclonal antibody option for when the Omicron BA.2 variant becomes predominant.

The FDA issued an EUA for tixagevimab with cilgavimab (Evusheld), a monoclonal antibody intramuscular injection, for preexposure prophylaxis for patients ages 12 years old and up who have moderate to severe immune compromise due to a medical condition or receipt of immunosuppressive medications or treatments and may not mount an adequate immune response to COVID-19 vaccination. Our local area has received a very small supply of this medication and Reading Hospital is contacting patients that qualify, prioritized based on a lottery process, as the supply permits.

HAVE WE ENTERED INTO THE ENDEMIC STAGE?

I think that the world is still in the pandemic stage transitioning to the endemic stage. A pandemic is when the world experiences widespread, exponentially increasing spread of infection. This is still occurring. Endemic viruses remain constantly present and have a fairly predictable spread, such as influenza and rhinovirus.

The US is seeing lower spread of Omicron due to the rapid uptick in cases during December and January that infected a significant proportion of our population including those with prior vaccination and prior infection. Those with prior immunity had less severe disease and those patients that received a booster had additional protection.

We are seeing increasing spread of the BA.2 Omicron subvariant in Europe and the US case counts of BA.2 are doubling every 1 – 2 weeks. I expect that we will see additional COVID-19 cases in Berks County and an increase in hospitalizations in the next month.

HAVE WE REACHED HERD IMMUNITY AND SHOULD HERD IMMUNITY BE OUR GOAL?

Our initial plan when the global COVID-19 pandemic began in 2020 was to reach herd immunity. Then, the reproductive number (Ro) was between 2 and 3, meaning that for one infected person, they infected 2-3 additional people. The reproductive number has continued to climb as subsequent variants became more infectious; approximately 7 for Delta, 8.2 for Omicron BA.1 and now 12 for BA.2. Comparing this to other viruses, Chickenpox Ro is 10, Mumps is 12 and Measles is 18. Due to this very high number, our goal is to protect as many patients as possible from severe disease requiring hospitalization and death through vaccination and tolerate mild break through infections.

WHAT SHOULD WE BE FOCUSED ON TO PREVENT RESURGENT CASES?

As a global society, we need to focus our vaccination efforts on those communities across the world that have not had access to vaccination. New variants will emerge from these communities and these variants will cause the future surges across the globe. Also, we should continue to promote vaccination and boosters for those who qualify. Fourth doses are recommended for immunocompromised patients and the FDA has issued an EUA for a fourth dose for patients over 65 years of age. Also, pharmaceutical companies are continuing the clinical trials to obtain EUA for a vaccine for children under 5 years of age. Vaccinating this age group is key to obtaining sufficient immunity in the community to decrease spread to highrisk patients.