Does the JNJ Covid Vaccine Safety Issue Present an Opportunity for Biopharma Investors?

Updated: Apr 21

Note: Originally posted on 4/18/21. See footnote for update info.

In an accompanying free blog post we discuss the recent rare blood-clotting side effects that may occur in all Covid vaccines, but likely are much more prevalent in some vaccines than others. Current data suggests that there is a safety advantage of mRNA vaccines over adenovirus vaccines. Thus, the market potential for J&J's vaccine, and possibly other adenovirus-based vaccines could be significantly reduced.

Which small/mid-cap COVID vaccine companies are using an adenoviral vector in the COVID vaccine candidates?

We used our new pipeline screener on, to find the answer. VXRT ($600M market cap), $ALT (market cap $435M), and IBRX ($6.7B market cap) are small and mid-cap COVID vaccine companies that utilize adenoviral vectors.

How likely is it that VXRT, ALT, and IBRX stock price will be significantly affected by further news this week and in the coming weeks regarding the J&J hold and the role of the adenovirus backbone in the side effects?

The value/price of neither VXRT, ALT nor IBRX were affected much by the J&J hold notice last week, although they all have been trending down in recent days along with the biopharma indices. Interestingly, all of these companies are testing different delivery mechanisms (oral or nasal) of their vaccine, and the VXRT and IBRX vaccines are directed to proteins in addition to the spike protein. Thus, there are variations in design that could have unknown effects on any possible blood-clotting side effect. Furthermore, especially for the J&J vaccine, the blood clotting side-effect is very rare (about 1 in 1 million). Taken together, and considering the relatively low implied volatility on these stocks currently, it seems likely that the J&J news will not affect VXRT and IBRX stock price too much this week, and in the coming weeks, unless a strong link is identified with adenoviral vectors and the thrombotic events with certain COVID-19 vaccines.

VXRT Covid=19 adenoviral vaccine

Are there any other small/mid-cap COVID vaccine companies that might benefit from the apparent superiority of RNA vaccines?

Check out our forum post of this article, for the answer to this question and detailed comparative information regarding the Moderna and Pfizer BioNTech vaccines. Plus, we've got detailed IQ cards on all the major COVID 19 clinical candidates and approved vaccines, as well as key upcoming catalyst dates. Just go to and sign up for a free 30-day trial (no credit card required) and get instant access to all this information.

Footnote: Originally posted on 4/18/21 but then split into 2 articles on 4/21/21. Updated on 4/19/21 to correct typos and add ALT to the adenoviral vector COVID vaccine list. Updated on 4/20/21 after listening to EMA press release today on the J&J vaccine rare safety issues.