Coronavirus Update 15

Pfizer vaccine vials in pizza boxes packed in dry ice

Two bits of good news merit mention. 

Initial indications of long-term immunity

The New York Times writes that some preliminary, not yet peer-reviewed, reports are coming out indicating that immunity to SARS-CoV-2 will likely be long-lasting. If the evidence turns out to be verified and true, this is a very big deal. It means that people might not need to be immunized every year or two, and instead, once they are immunized, they may not need to be re-immunized for years. 

The big caveat here is that the data is from people who recovered from an infection. Vaccines may not generate the same kind of response, so that needs to be investigated in the coming months. But at least, it is possible (likely?) that once a person recovers from an infection, they will remain immune for a long time. There may be some exceptions to that, but the data so far suggests that is rare. The hope is that vaccine responses will be similar to immune responses to natural infection that immunity will last for years instead of just months.

The NYT writes:

How long might immunity to the coronavirus last? Years, maybe even decades, according to a new study — the most hopeful answer yet to a question that has shadowed plans for widespread vaccination.

Eight months after infection, most people who have recovered still have enough immune cells to fend off the virus and prevent illness, the new data show. A slow rate of decline in the short term suggests, happily, that these cells may persist in the body for a very, very long time to come.

“That amount of memory would likely prevent the vast majority of people from getting hospitalized disease, severe disease, for many years,” said Shane Crotty, a virologist at the La Jolla Institute of Immunology who co-led the new study.

The findings are likely to come as a relief to experts worried that immunity to the virus might be short-lived, and that vaccines might have to be administered repeatedly to keep the pandemic under control.  

And the research squares with another recent finding: that survivors of SARS, caused by another coronavirus, still carry certain important immune cells 17 years after recovering.

The findings are consistent with encouraging evidence emerging from other labs. Researchers at the University of Washington, led by the immunologist Marion Pepper, had earlier shown that certain “memory” cells that were produced following infection with the coronavirus persist for at least three months in the body.

A study published last week also found that people who have recovered from Covid-19 have powerful and protective killer immune cells even when antibodies are not detectable.

In addition to the Pfizer vaccine, another vaccine by Moderna has been shown to be equally effective with the Pfizer product. Moderna is lagging Pfizer by maybe a couple of months, maybe less, so a second vaccine might begin to be available by Q2 or Q3 of 2021, maybe end of Q1.

Vaccine manufacturing and distribution is very complex but on track for 2021

Pfizer reported last week that its vaccine was about 90% effective. Now all the data is in and the final data indicates it is about 95% effective. This vaccine is complicated by a requirement to be shipped at dry ice temperature, about -94ᵒ F. The company plans to apply for emergency use authorization within the next several day. The Washington Post writes:

At the core of Pfizer and BioNTech’s vaccine is a powerful but fundamentally transient and unstable genetic material called messenger RNA, ensconced in lipid nanoparticles — tiny fat bubbles. The messenger RNA encodes the blueprint for the hallmark spiky proteins that stud the surface of the coronavirus and, once inside a person’s body, it instructs cells to build replicas of the spike. Those harmless versions teach the immune system to recognize the real thing — in essence, turning the human body into a vaccine factory.

The technology has never been used in an approved medical product. That means Pfizer and BioNTech are inventing the recipes — and tinkering with them to increase the output at almost the same time.

If Pfizer receives the regulatory green light, its freezer farm will become a distribution center, the pizza boxes submerged under 50 pounds of dry ice and sent to points of vaccination, which will be determined by states but could include locations such as hospitals or pharmacies. By the end of the year, Pfizer anticipates sending thousands of shipments each day from Kalamazoo and a second freezer farm in Pleasant Prairie, Wis.

Upon arrival, the thermal shippers must be refreshed with dry ice or the vials must be transferred to ultra-low-temperature freezers. The specifications are exacting if the vials stay in the shippers — the cooler is not to be opened more than twice a day, must be refreshed with dry ice every five days and is designed to be used for 15 days. The vials can stay at refrigerator temperatures for five days before their contents degrade.

The ultracold storage requirement for the vaccine will add a wrinkle to an unprecedented vaccination campaign. Rolling out such a vaccine in the developed world will be challenging; doing so in the developing world could be nearly impossible. The next phase of vaccine production involves creating a more stable freeze-dried version and expanding production capabilities, for example, by finally building those bigger pizza ovens that could make formulation go faster.

Throughout the vaccine effort, government officials have projected hopeful timelines about when doses will be available: High-risk people may be able to get vaccines in the first months of next year, the rest of the population later in the spring and summer. Beneath those projections is a labyrinthine scientific and industrial process, with each node — hundreds of people’s work — coming together to bring the world closer to ending the pandemic.

This is completely new vaccine technology. No RNA vaccine has ever been developed and FDA approved for use in humans. The Moderna uses a completely different technology, which also has never been developed and approved. To meet demand for dry ice, Pfizer is building a dry ice factory on its manufacturing site. The dry ice requirement will probably severely limit the use of this vaccine in third world countries.