VAERS reports by lot
Pfizer COVID-19 lot MY9548: VAERS reports
65 VAERS reports list lot MY9548 as a Pfizer COVID-19 vaccine, received between 2025-09-15 and 2026-04-27. Data: VAERS public files through 28 May 2026 (site extract 2026-10-28).
Read this first. VAERS accepts reports from anyone, and a report does not establish that the vaccine caused the event. A lot's report count mostly reflects how many doses it contained, when it was used and who received it; no administered-dose counts are published for this lot, so counts are not rates and cannot rank lots against each other. Lot numbers in VAERS reports are typed by reporters and are sometimes wrong.
65
Reports
5%
Marked serious
1
With a death outcome
8
Months with reports
Symptom categories in these reports
A report can mention several categories, so the counts add up to more than the number of reports.
| Category | Count | % |
|---|---|---|
| Injection-site / Local reaction | 60 | 32% |
| General / Systemic (non-local) | 32 | 17% |
| Neurological | 30 | 16% |
| Musculoskeletal | 21 | 11% |
| Cardiac / Cardiovascular | 20 | 11% |
| Gastrointestinal | 10 | 5% |
| Dermatological (non-injection-site) | 6 | 3% |
| Respiratory | 3 | 2% |
| Thrombotic / Hematological | 2 | 1% |
| Psychiatric / Neuropsychiatric | 2 | 1% |
| Allergic / Anaphylactic | 1 | 1% |
Where reports came from
U.S. state of the reporter, where given (top 12).
| State | Reports |
|---|---|
| California | 7 |
| Texas | 6 |
| Wisconsin | 4 |
| Massachusetts | 4 |
| Illinois | 4 |
| Missouri | 3 |
| Michigan | 3 |
| Minnesota | 3 |
| Virginia | 3 |
| Ohio | 2 |
| Pennsylvania | 2 |
| New York | 2 |
Reports by month received
| Month | Reports | Bar |
|---|---|---|
| 2025-09 | 5 | |
| 2025-10 | 33 | |
| 2025-11 | 14 | |
| 2025-12 | 5 | |
| 2026-01 | 4 | |
| 2026-02 | 1 | |
| 2026-03 | 2 | |
| 2026-04 | 1 |
Products recorded with this lot
- COVID-19 (primary series) — Pfizer-BioNTech (61 reports)
- COVID-19 (additional/booster) — Pfizer-BioNTech (4 reports)
Manufacturer and product as reported in VAERS. Reports listing the lot under more than one product are counted once.
Related
- All Pfizer COVID-19 lots with VAERS reports
- COVID-19 vaccine lot number lookup
- COVID-19 vaccine side effects, trials and ingredients
- Comirnaty: ingredients, package insert and side effects
- Look up a lot for any vaccine
Nearby Pfizer COVID-19 lots (A–Z): MD3414 · ME6072 · MY9547 · MY9550 · NA0587 · NA0589
Source: VAERS public data (CDC/FDA), grouped by manufacturer and lot by the Open Source Medicine Foundation; extract 2026-10-28 18:08 UTC. Not medical advice. Report errors via contact.