vaccines

4 Articles

Mechanisms Behind Vaccine Side-Effects: The Science That Causes That Sore Arm

September 21, 2021 by 85 Comments

After receiving a vaccination shot, it’s likely that we’ll feel some side-effects. These can range from merely a sore arm to swollen lymph nodes and even a fever. Which side-effects to expect depend on the exact vaccine, with each type and variant coming with its own list of common side-effects. Each person’s immune system will also react differently, which makes it hard to say exactly what one can expect after receiving the vaccination.

What we can do is look closer at the underlying mechanisms that cause these side-effects, to try and understand why they occur and how to best deal with them. Most relevant here for the initial response is the body’s innate immune system, with dendritic cells generally being among the first to come into contact with the vaccine and to present the antigen to the body’s adaptive immune system.

Key to the redness, swelling, and fever are substances produced by the body which include various cytokines as well as prostaglandin, producing the symptoms seen with inflammation and injury.

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This Isn’t Your Father’s Yellow Card

February 1, 2021 by 59 Comments

As the global vaccination effort rolls out in many countries, people will increasingly be required to provide evidence for various reasons, especially travelers. Earlier this month a coalition which includes Microsoft, the Mayo Clinic, Oracle, MITRE, and others announced an effort to establish digital vaccination records called the Vaccination Credential Initiative (VCI). This isn’t going to be a brand new thing, but rather an initiative to provide digital proof-of-vaccination to people who want it, using existing open standards:

  • Verifiable Credentials, per World Wide Web Consortium Recommendation (VC Data Model 1.0)
  • Industry standard format and security, per the Health Level Seven International (HL7) FHIR standard

In addition, the World Health Organization formed the Smart Vaccination Certificate Working Group in December. Various other countries and organizations also have technical solutions in the works or already deployed. If a consensus doesn’t form soon, we can see this quickly becoming a can of worms. Imagine having to obtain multiple certifications of your vaccination because of non-uniform requirements between countries, organizations, and/or purposes.

Older readers and international travelers may be wondering, “don’t we already have a vaccination card system?” Indeed we do: the Carte Jaune or Yellow Card. The concept of a “vaccination passport” was conceived and agreed upon at the International Sanitary Convention for Aerial Navigation in 1933. Over the years the names and diseases of interest have changed, but since 2007 it has been formally called the International Certificate of Vaccination or Prophylaxis (ICVP). In recent times, yellow fever was the only vaccination of interest to travelers, but other vaccinations or booster shots can be recorded as well. One problem with the paper Yellow Card is that it is ridiculously easy to forge. Nefarious or lazy travelers could download it from the WHO site, print it on appropriate yellow card stock, and forge a doctor’s signature. The push for a more secure ICVP is not completely unreasonable.

Reading the instructions on the Yellow Card brings up a couple of interesting points:

  • This certificate is valid only if the vaccine or prophylaxis used has been approved by the World Health Organization — Currently the Pfizer vaccine is the only one to be approved by WHO, and even that is only an emergency approval. If you receive a non-Pfizer vaccination, what then?
  • The only disease specifically designated in the International Health Regulations (2005) for which proof of vaccination or prophylaxis may be required as a condition of entry to a State Party, is yellow fever — This one is interesting, and suggests that member states cannot require proof of Covid19 vaccination as an entry requirement, a situation that will no doubt be quickly revised or ignored.

Note: This writeup is about vaccinations, not about immunity. While immunity certificates have been used from time to time throughout modern history, the concept of an international immunity passport is not well established like the ICVP.

The High-Tech Valor Glass Vials Used To Deliver The Coronavirus Vaccine

December 28, 2020 by 70 Comments

As the world waits for COVID-19 vaccines, some pharmaceutical companies stand armed and ready with an exciting improvement: better vials to hold the doses. Vials haven’t changed much in the last 100 years, but in 2011, Corning decided to do something about that. They started developing an alternative glass that is able to resist damage and prevent cracks. It’s called Valor glass, and it’s amazingly strong stuff. Think Gorilla glass for the medical industry.

Traditionally, pharmaceutical vials have been made from borosilicate glass, which is the same laboratory-safe material as Corning’s Pyrex. Borosilicate glass gets its strength from the addition of boron. Although borosilicate glass is pretty tough, it comes with some issues. Any type of glass is only as strong as its flaws, and borosilicate glasses are prone to some particularly strength-limiting flaws. Pharmaceutical glass must stand up to extreme temperatures, from the high heat of the vial-making process to the bitterly cold freeze-drying process and storing temperature required by the fragile viral RNA of some COVID-19 vaccines. Let’s take a look at how Valor glass vials tackle these challenges.

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The Special Fridges Behind The COVID-19 Vaccine, Why It’s Surprisingly Difficult To Be That Cool

November 17, 2020 by 162 Comments

One of the big stories last week was the announcement of results from clinical trials that suggest a new COVID-19 vaccine developed through the joint effort of the American and German companies Pfizer and BioNTech is strongly effective in providing immunity from the virus. In the midst of what is for many countries the second spike of the global pandemic this news has been received with elation as well as becoming the subject of much political manoeuvring.

While we currently have two vaccine candidates with very positive testing results, one of the most interesting things for us is the need to keep doses of the Pfizer/BioNTech vaccine extremely cold until they are administered. Let’s dig into details of the refrigeration problem at hand.

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