Francisco R. Velázquez, M.D. COVID-19 New Variants - What could the impact be this summer?

By Francisco R. Velázquez, M.D., S.M., FCAP

Over the past few weeks, we have heard about new coronavirus variants and the new nomenclature adopted by the World Health Organization (WHO), using letters of the Greek alphabet to identify COVID-19 variants. At this point we are tracking 11 variants worldwide, from Alpha (B.1.1.7) to Lambda (C.37). In the United States, the Centers for Disease Control and Prevention (CDC) is currently following 15 different variants. The difference in number is due to the geographical distribution of some variants. Some are more frequently seen internationally while some have more of a domestic presence. We have at least seven of these variants in Spokane County.

For this summary we are going to focus on three specific variants. These are: B.1.1.7 (alpha), P1 (gamma) and B.1.617.2 (delta). The alpha variant was first identified in the United Kingdom last December and quickly became the most sequenced variant in England. This variant was first detected in the U.S. in January and quickly became the predominant variant by spring.

The gamma variant is traced back to Manaus of Brazil in September of 2020. It spread rapidly across the country, internationally, and made its way to Spokane by April of this year.

Most recently, the delta variant, initially identified in the Indian state of Maharashtra in December of 2020, became the predominant variant in India. During the most recent surge, this variant accounted for up to 90% of all infections in India. The first cases of delta in the U.S. were detected in March. The European Centre for Disease Prevention and Control suggests this variant may account for 90% of all COVID-19 cases in the European Union by late August. It also appears this variant is the cause behind surges in Russia, Indonesia and several other countries.

In the U.S., recent studies suggest the delta and gamma variants are replacing the alpha as the dominant variant in the country. This is in contrast to what has been observed in England where delta has replaced the alpha as the dominant variant and accounts for up to 90% of new infections.

Why is this important? First, these variants are more effective at transmission compared to the wild type (original strain). Earlier data suggests alpha is about 50% more transmissible than the original strain, and delta is suggested to be 225% more transmissible. Those infected have about 1,000 times more copies of the virus in their respiratory tract than those infected with the wild type. Preliminary evidence and data from England and Scotland indicate people infected with the delta variant are about two and a half times more likely to end up in the hospital.

In Washington, we are seeing cases of the gamma variant associated with hospitalizations and breakthrough cases (fully vaccinated individuals who test positive or clinically have the infection). Recently published research demonstrated a growth curve for the delta variant to be faster in counties with lower vaccination rates. Gamma, which may be less transmissible than delta, is also more common in counties with lower vaccination rates.

The good news is both m-RNA vaccines (Pfizer-BioNTech and Moderna) and the viral vector vaccines (Johnson & Johnson) seem to be quite effective against the delta variant. That may not be the case against the gamma variant; early research suggests vaccines offer reduced protection from infections caused by this strain. Therefore, full immunization is very important. Those who are fully immunized appear to be well protected from infections with delta variants. However, people with only one dose of the m-RNA vaccines are not as protected.

After many weeks of steadily decreasing COVID-19 cases in the U.S., the number of new daily cases rose almost 15% during the last week of June compared to the previous seven days. This increase is more prominent in the southern and western regions of the country. The increase is likely due to infections caused by the delta variant. Similar increases are being observed in many other countries. Interestingly, we do know only about 10,000 cases have been recorded in fully vaccinated people. In addition, they represent 0.14% of current hospitalizations and less than 1% of all COVID-19 related deaths, even with the current variants circulating.

It seems that a likely scenario for this summer is one in which we see variants such as delta and gamma displace the previously dominant alpha. This could lead to an increase in cases particularly in unvaccinated people who are at a higher risk for infection and hospitalization. On June 28, the Los Angeles County Department of Public Health issued a recommendation for indoor masking regardless of vaccination status as a precaution due to the increase in cases of the delta variant. Data from sequencing analysis demonstrated the delta is about 50% of current cases there.

We have made a lot of progress in Spokane County over the past 18 months; we have come a long way. For us to protect the freedoms we have gained, vaccines are the key.

Let’s get immunized. Doing so, along with taking reasonable precautions to limit transmission, will protect those around you who cannot be immunized.

Francisco R. Velázquez, M.D., S.M., is the interim health officer for Spokane Regional Health District.