POLICY BRIEFING – WEEK IN REVIEW
Pfizer vaccine implementation limitations. Was last week's major announcement actually 'news we can use'? Not if it can't reach you
Pfizer and Biontech made headlines last week with their announcement of a vaccine candidate that they say has demonstrated 90 percent efficacy in preventing covid-19 symptoms in participants who had no evidence of previous infection–though we do not yet know whether this means infections and spread of disease was prevented, as a Brief19 analysis showed.
Nevertheless, while the possibility of an effective vaccine remains exciting, it is important to look at the limitations for this particular vaccine, in particular those relating to its storage requirements. The first is the temperature; this vaccine must be kept at no greater than negative 70 degrees Celsius (-94 degrees Fahrenheit), and specialized freezers are required to maintain this level of cold. The necessary equipment is uncommon or lacking in many locations outside of urban and specialized medical centers both in the US and abroad. When stored at this temperature, the vaccine can last up to six months, but the genetic material (mRNA) that forms the core of the vaccine starts deteriorating (denaturing) after just five days of normal refrigeration. Proper storage also requires a specific type of thermal-resistant glass to avoid shattering, which could lead to shortages during the initial ramp up period.
Aside from the requirements of on-sight storage, transportation logistics also remain a major hurdle. Pfizer has created special storage containers that use dry ice to maintain the proper temperature, buying anywhere from ten to twenty five days of storage, but frequency of opening and replenishment will alter the effective shelf life. Additionally, boxes of the vaccine carry between one thousand and five thousand doses, a number that likely exceeds a physician's or pharmacy's ability to distribute all of the lots before the five day viability expires. This is why some states are considering centralized vaccination centers. Unfortunately, some states lack the resources to fund such an endeavor; this, combined with many of the most vulnerable patients unable to travel long distances to reach such centers, leaves some of the anticipated problems around vaccine rollout unsolved. Various. 16 November 2020.
When SARS-CoV-2 first made international headlines, I did not think we were headed for a year of disrupted life. I was wrong about that because I believed we could test our way out of systemic lockdowns and long-term alterations in life-as-we-know-it. With aggressive enough testing strategies (a test for every person in the United States) my hope was that we could isolate the cases we detected, have local lockdowns, and get back to life. We'd do aggressive surveillance testing of asymptomatic people (random tests, especially among workers who interact with the public) and do mini-shutdowns as needed. We never got there. Why? Because we let the virus spiral out of control before we had enough tests to achieve anything close to this vision.
Not so in China. A new report out of Qingdao, China in the New England Journal of Medicine describes a massive testing strategy that was unrolled in just a matter of days after three cases were detected there following a two-month period without any cases. Nearly 11 million people were tested at 4,090 testing sites in an approximately five-day period. This led to the identification of 12 total cases. Pooled testing was done for efficiency. (For more on that, read the CDC's guidance on the topic). Residents were not allowed to use public transit until they were tested and had to wear masks when outside. With so few cases, it is clear that they caught the outbreak early. In fact, contact tracing appears to have been completely successful, an unprecedented achievement at this scale during the covid-19 pandemic.
This approach was only possible because the region started with zero cases and had the ability to rapidly scale up testing. At the time of publication, the outbreak had been completely controlled, and—as per the authors—this was accomplished "without a lockdown." Our expert assessment: hot damn. 19 November 2020.