The known unknowns – how is the Delta variant impacting vaccine efficacy?

• In today’s Recommendations for Industry, TAG discusses the Delta variant impacting vaccine efficacy. Read more below.
• Nearly 72K children test positive in the past week; heart problems associated with vaccines are uncommon, study shows. The lambda variant, first detected in Peru in August 2020, made its way to the U.S. for the first time on July 22 and now accounts for 1,053 cases in the country. The lambda variant isn’t yet showing signs to spark concern about it becoming the dominant strain of COVID-19 in the United States like delta. For every one million Americans vaccinated against COVID-19, only 60 developed heart problems, according to a new study published in the JAMA Network.
• Delta variant is ravaging the world but it’s pushing Southeast Asia to breaking point. Outbreaks in Vietnam, Indonesia, Malaysia, Thailand, and Myanmar are increasing substantially. The countries are suffering a health crisis, with hospitals stretched to their limits, full cemeteries expanded to hold the Covid dead, and exhausted health care workers.
• Moderna’s Covid vaccine 93 percent effective 6 months after second dose, company says. That compares favorably to data from Pfizer Inc and BioNTech SE last week in which they said their vaccine’s efficacy waned around six percent every two months, declining to around 84 percent six months after the second shot. Moderna said its studies of three different booster candidates induced robust antibody responses against variants, including the Gamma, Beta and Delta variants.
• Fauci fears a COVID variant worse than Delta could be coming . As the virus continues to spread due to insufficient vaccination rates, it is being given “ample” time to mutate into a more dangerous new variant in the fall and winter, Fauci said. On Tuesday South Korea announced that it had detected two cases of the Delta Plus variant, one in a man who had recently returned from the U.S., Reuters Some experts believe the Delta Plus variant could be more contagious than the Delta variant. Recent studies indicated that Lambda could be more resistant to the current COVID-19 vaccines, according to Reuters.
• US plans to require COVID-19 shots for foreign travelers.  The requirement would come as part of the administration’s phased approach to easing travel restrictions for foreign citizens to the country. No timeline has yet been determined, as interagency working groups study how and when to safely move toward resuming normal travel. Currently, non-U.S. residents who have been to China, the European Schengen area, the United Kingdom, Ireland, Brazil, South Africa and India in the prior 14 days are prohibited from entering the U.S. All travelers to the U.S., regardless of vaccination status, are required to show proof of a negative COVID-19 test taken within three days of air travel to the country.
• Here’s How You Can Show Proof of Vaccination in New York City: a new app released by the city, called NYC Covid Safe; the state’s Excelsior Pass; or by simply showing your paper vaccination card or a copy of your official vaccination record. Mayor Bill de Blasio’s announcement on Tuesday that people participating in indoor activities at restaurants, gyms, movie theaters and performances in New York City must soon show coronavirus. This will begin on August 16. This will not be fully enforced until September 13. Children under 12 are still not yet eligible to receive any of the vaccines. On Wednesday morning, Mr. de Blasio said that they would be allowed to enter restaurants with vaccinated adults if they are masked.

Food Safety/Public Health:

• COVID-19 not a food safety hazard – FAO Current data indicates that neither food nor food packaging is a pathway for the spread of viruses such as SARS-CoV-2. An infected worker can infect co-workers, contaminate the food production and processing environments, and food or food materials that may lead to trade restrictions, even though there is no food safety hazard. The virus is susceptible to most used disinfectants and sanitizers used in the food processing environment. WHO recommends sanitizers with greater than 70 percent alcohol with sufficient contact time for decontamination.

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The known unknowns – how is the Delta variant impacting vaccine efficacy? 

At this point, it’s likely that we all know someone, or have heard of someone, who is fully vaccinated and had a breakthrough infection.  It’s also likely that the fully vaccinated person had mild to moderate symptoms, ranging from a light a cold to the moderate flu.  With our understanding of vaccine efficacy upended last week when the CDC published a report on the Provincetown outbreak, we learned that the efficacy of the vaccines may be much lower than we thought.  Approximately 75% of cases in that outbreak were fully vaccinated, but that doesn’t mean the vaccines are now only 25% effective.  So what is the current vaccine effective rate against the Delta variant?

Delta emerged this spring in India, at a time when only 1-3% of the population in that country was fully vaccinated, so the Delta variant mutation favors increased transmission in an unvaccinated population and not necessarily mutations that favor vaccine evasion.  Other emerging variants, such as Lambda, do appear to have the ability to evade current vaccines more effectively.

The largest and most robust study looking at vaccine efficacy against the Delta variant was conducted in the UK and found that the Pfizer mRNA vaccine was 31% effective after one dose and 88% effective after two doses.  This contrasts recent data published by the Israeli Ministry of Health showing the efficacy of the Pfizer vaccine may be as low as 39% when looking at breakthrough infections in June and July in Israel.  These data have been critiqued for the small sample size and study design.

While it is likely that the true vaccine efficacy against the Delta variant is somewhere between these numbers, it’s important to remember that vaccine protection against severe illness remains high, at over 90% in all studies.  The most important lesson from the Provincetown outbreak shows that higher risk activities, such as sustained close-contact in poorly ventilated spaces and large crowds, decreases protection of infection in fully vaccinated people.

As businesses plan to reopen offices and children return to school, there is less confidence that vaccinated people are fully protected against infection.  While we wait for more definitive data on vaccine efficacy against the Delta variant in the US, we also know that blending risk mitigation strategies such as masking in indoor spaces, testing unvaccinated people, and improving ventilation provide a layered approach to risk reduction.  Unfortunately, the Delta variant shows us that we need to be ready to take in new information about the virus and temporarily adjust our behaviors and controls until cases decrease.  As more people are vaccinated in the US and globally, the severity of future surges will decrease and we will learn to manage Covid, much like influenza. At TAG, we’ll continue following and interpreting the emerging science on the Delta (and future) variants.

Matrix

Displayed through TAG’s matrix, case and hospitalization rates have been rising rapidly throughout the US over the last two weeks with cases increasing 139% and hospitalizations increasing 79%. States in which over 50% of the population are fully vaccinated are experiencing lower per capita rates of infection and hospitalizations. Many states now have case rates above a seven-day average daily rate of 14 per 100,000 (the CDC definition of High Transmission).

• When You’ve Been Fully Vaccinated, the CDC recently emphasized that wearing a mask to maximize protection against the new Delta variant can prevent possible spreading to others. Wearing a mask in areas that are required by law, regulations, or local guidance should be continued.
• Here’s how schools should handle a Covid-19 outbreak, experts say: the largest step that will be taken by school officials is to reach out to their local health department when a case arises in order to track any close contacts. The steps needed to control a Covid-19 outbreak within a school would be like steps taken for any outbreak of a communicable disease in a school, such as measles. The Delta variant can be as transmissible as chickenpox and one infected person could spread the variant to about five to nine other people on average – whereas, with the original strain of the coronavirus, one infected person could spread it to two to three people on average.
• China orders mass testing in Wuhan as COVID outbreak spreads: The current outbreaks, while still in the hundreds of cases in total, have spread much more widely than previous ones, reaching multiple provinces and cities including the capital, Beijing. Many of the cases have been identified as the highly contagious delta variant that is driving a resurgence in many countries.
• One-third of all COVID cases reported in Florida and Texas; US reaches 70% of partially vaccinated adults: COVID-19 updates Florida broke two records — in cases and hospitalizations — this weekend. Texas now has more total statewide deaths than New York, the early epicenter of the pandemic in the United States. The U.S. reported 599,334 cases in the week ending Sunday. A week earlier, cases numbered 364,123. The nation is now reporting 2,500 deaths per day, according to USA TODAY analysis of Johns Hopkins University data.
• The COVID culture war: At what point should personal freedom yield to the common good? After more than 18 months of a pandemic, with 1 of every 545 Americans killed by COVID-19, a substantial chunk of the population continues to assert their own individual liberties over the common good. COVID-19 is now killingmore than 2,000 Americans each week, according to data from Johns Hopkins University, with new infections topping 60,000 a day for the first time in more than three months.