Vaccinations Archive

In the US, widespread vaccination halted the ongoing spread of measles more than 20 years ago, but recent outbreaks have flared in over 20 US states, leading to hospitalizations and at least two deaths. Measles is highly preventable — here’s what you need to know.

Early signs of cervical cancer can include blood-tinged vaginal discharge, heavier discharge than usual, spotting or bleeding between periods, menstrual flow that’s heavier or lasts longer than usual, bleeding or pain during or after intercourse, and vaginal bleeding after menopause.

Science has made astonishing progress in the past 60 years in many areas. Examples include the ability to repair certain defective genes, use stem cells to treat certain diseases, detect and fight many cancers, fight viruses with medications, make organ transplants work, and prevent disease with vaccines and lifestyle changes. Thanks to technological advances, doctors can also see clearly inside the body and use artificial intelligence to speed the development of new medications.

Shingles occurs when the dormant chickenpox virus reactivates, causing tingling, burning, and a painful, blistering rash. Shingles can affect anyone who has had chickenpox, with higher risk after age 50 and in people with weakened immunity. Diagnosis and treatment within three days of the rash appearing can shorten the illness and reduce severity. Most people recover completely from shingles, but there may be complications, such as post-herpetic neuralgia, which is pain that can be severe and long-lasting. Vaccination is the best way to prevent shingles and its complications.

A 2025 study suggests that respiratory syncytial virus (RSV) can lead to heart-related complications, such as a heart attack, chronic heart failure, or an irregular heartbeat—even in people without a previous heart condition.

A 2025 study found that people who had received a shingles vaccination had lower risks for stroke and various types of heart disease, including heart failure and heart attacks, compared with people who didn’t receive a shingles vaccine.

Getting vaccinated against influenza (flu), COVID-19, and pneumonia is especially important for people who have cardiovascular disease. The coughing and congestion that commonly occur with respiratory infections can make breathing more difficult, and the potential drop in oxygen puts added stress on the heart. Serious infections sometimes trigger sepsis, which happens when the immune system is overwhelmed or goes into overdrive, causing symptoms such as a rapid heart rate, very fast breathing, and low blood pressure. These complications can lead to a heart attack.

There are currently nine trials of vaccines for Alzheimer’s disease under way. All of them are in people with mild Alzheimer’s or with the pre-Alzheimer’s condition called mild cognitive impairment. All of the vaccines are designed to encourage the immune system to remove protein deposits from the brain. Most experimental vaccines are given by injection; one being tested at Harvard Medical School uses a nasal spray. It will be several years before we know if any of them will work.

With influenza virus, a new vaccine must be developed each year to adapt to the virus’s changing structure.

Arm tenderness is the most common side effect after vaccination. The injection stretches muscle fibers and triggers an immune response, causing discomfort. People can counter pain by moving the injected arm afterward and applying a cool compress or ice pack.