Skip to content

When you choose to publish with PLOS, your research makes an impact. Make your work accessible to all, without restrictions, and accelerate scientific discovery with options like preprints and published peer review that make your work more Open.

PLOS BLOGS Absolutely Maybe

A Process Update on Covid Vaccine Tracking

Scientist presenting tangled mess of a chart at a conference, saying "As you can see, this slide provides a simplified overview of the 46-armed phase 1/2/3 trial of the vaccine." (Cartoon by Hilda Bastian.)

Tracking Covid vaccine development from early in the pandemic was a wild ride. Since 2020, I’ve written 36 posts here on Covid vaccines, crammed with a lot of detail and news on trials and results. One of those posts over a year ago explained why I decided to track Covid vaccines so intensively, and how I went about it.

Since then, most other Covid vaccine trackers have stopped, including The New York Times in August, Bloomberg in October, and the Covid-19 Vaccine Tracker for clinical trials in December. The WHO tracker is still updated, though, which helps a lot – but as excellent a resource as it is, it still doesn’t have what I need to keep up with what’s happening. Enough other people who don’t have time to hunt this all out themselves, including some in vaccine development, find what I gather helpful, too. And there’s personal interest as well, of course.

So I decided to keep going – but with some changes in process to save time, and to focus on next generation vaccines. For Covid vaccines generally, that means I spend less time on searching, linking, and categorization – the collection of general records is less comprehensive and more messy.

However, for 2 types of next generation vaccines, the collection is still heavily curated, and very comprehensive. Those types are mucosal vaccines – intranasal and other vaccines aiming for first line of defense immunity – and pancoronavirus vaccines – vaccines that are trying to achieve protection against not only all SARS-CoV-2 viruses that cause Covid, but immunity to a broader range of potentially dangerous coronaviruses.

My first updates in this re-focused vaccine tracking were in April 2023: part 1 covered mucosal vaccines, and part 2, pancoronavirus vaccines.

For those types of next generation vaccines, I’m trying to include every vaccine that’s gotten as far as releasing any results – preclinical or clinical – and/or has a clinical trial underway.

There’s a third type of next generation vaccine – vaccines that aim to be more or less variant-proof for SARS-CoV-2. That’s not as easy a group to categorize, and it’s a far bigger group. Although it won’t be a comprehensive collection like the others, I’m going to tag records that I come across in my searching that stand out for clear attempts to provide protection against all variants.

Based on what’s been happening with next generation vaccines in the last year, my current tentative plan is to do more frequent updates, incorporating developments with all types of next generation vaccines, or if there is a particular major development. I’m not sure how often that will be, but my hope is that I’ll be running searches every couple of weeks or so, if not every week.

You can keep up with news of these posts, along with my other writing, via my newsletter, Living With Evidence. And I’m active on Mastodon: 

For technical details on my publicly accessible collection of Covid vaccine records and my search process, keep scrolling, or you can jump to:

  • Notes on the Zotero collection of Covid vaccine records.
  • General search strategy (original and current).


Cartoon of facing off coronavirus

All my Absolutely Maybe Covid-19 vaccine posts

All previous Covid-19 posts at Absolutely Maybe

My posts at The Atlanticat WIRED, and debunking posts at my personal website.

Disclosures: My interest in Covid-19 vaccine trials is as a person worried about the virus, as my son is immunocompromised: I have no financial or professional interest in the vaccines. I have worked for an institute of the NIH in the past, but not the one working on vaccines (NIAID). More about me.

The cartoons are my own (CC BY-NC-ND license). (More cartoons at Statistically Funny.)

Notes on the Zotero collection 

You can dig into my collection of records for vaccines here.

This is a publicly accessible collection I update regularly. It includes any Covid-19 vaccine with any published preclinical and/or clinical trial results. Once a vaccine is in the collection, clinical trial register entries for that vaccine are also added.

There are 3 categories where a vaccine is added even if there have been no preclinical or trial results for it:

  • A phase 3 trial registration is identified for any type of vaccine.
  • Any clinical trial is identified for a mucosal vaccine.
  • Any clinical trial is identified for a pancoronavirus vaccine.

When trials are registered in more than clinical trials registry, the multiple records may or may not be in the collection: If I have located a record in, I do not hunt for additional registrations. For my own convenience in keeping an overview of vaccine progress, when preprints appear later in journals, I replace the original record with the journal article. Preprints may also be uploaded to multiple preprint servers: rather than check if versions have differed, I keep the first preprint in the collection (sometimes over-written with updates in the same server), unless I saw that a version that seems markedly different.

Records are tagged to identify the vaccine, and the type of record it is (eg trial registration, or for results, “preclinical”, “phase 1” etc).

Mucosal vaccines are also tagged “mucosal”, and pancoronaviruses are tagged “coronaviruses”. Vaccines that are adapted for variants are also tagged. If a trial includes any under-18s, then its records are tagged “trial with children/teens”.

General search strategy

I do additional searching for next generation Covid vaccines, including searching developer and manufacturer websites. The basis for the tracking process, though, is a general search for Covid vaccines with preclinical or trial results, trial registrations for those vaccines, and any phase 3 trial registrations.

My original search process was described in detail in my February 2022 post. I was running a wide range of searches nearly every day for a long time. My current plan is to try to run the new searches every couple of weeks or so at least. This table shows the original regular general searches, and the modified one starting 2023.

From 2020 to 2022 From 2023
PubMedvaccine[ti] AND
(“sars-cov-2″[ti] OR “covid-19″[ti])
(vaccine[ti] AND
(“sars-cov-2″[ti] OR “covid-19″[ti]))
NOT hesitan*
PMC(TITLE:”sars-cov-2″ OR TITLE:”covid-19″)
AND (TITLE:”vaccine”)
bioRxiv, medRxivAll tagged CovidAll tagged Covid
Research Squaren.a.All tagged Covid
ClinicalTrials.govSARS CoV 2 infection AND vaccineSARS CoV 2 infection AND vaccine
  1. As someone who’s in the immunocompromised category and has been feeling really discouraged, your posts give me hope and patience. Thank you SO much for doing all this work for us!!!

Leave a Reply

Your email address will not be published. Required fields are marked *

Add your ORCID here. (e.g. 0000-0002-7299-680X)

Related Posts
Back to top