While Steven Salzberg's readers-response letter may accurately reflect his point of view ("Sun gives voice to dangerous anti-vaccination fear-mongering," July 13), he significantly mischaracterizes important aspects of my July 11th op-ed, "We don't know enough about childhood vaccines."

The main point of my op-ed is a simple fact, a number. The federal government recommends 36 doses of vaccines for every child during the first two years of life. And then I ask: Is this too many, too few or just right? What is "dangerous" is to ignore this fact, and to lack the curiosity or backbone to fully explore the science to understand — and, if necessary ameliorate — any negative consequences of this number for our youngest citizens.

Providing facts — drawn from Centers for Disease Control and Prevention reports and meticulously checked with the lead author of the federal "General Recommendations on Immunization" — is not, as Mr. Salzberg asserts, "fear-mongering" and "misinformation."

Rather, knowing this number is vital to ensuring that there is ongoing, rigorous biomedical research about childhood vaccines and the vaccine schedule. After all, more than 4 million U.S. children are born each year, and these federal recommendations apply to each and every one of them. These infants deserve more than reliance on a decade-old analysis of the ever-changing vaccine schedule, and name calling. Facts and data are, or should be, the way we have an informed populace, good science, sensible policies, and a strong democracy.

Mr. Salzberg asserts that the content of my op-ed "will lead parents to withhold vaccines from their children." My article does not say this. That is his conclusion, not mine.

Mr. Salzberg sets up a straw man, saying my "main claim is that the current vaccine schedule gives children too many vaccines too early in life, and that is somehow harmful to children." My article does not say that, either. Rather, it presents facts and asks questions, leaving readers to draw their own conclusions.

I do not know what Mr. Salzberg means when he says "science has debunked Ms. Dunkle's claims." What "claims" in my article is he talking about? Or perhaps he is speaking about issues on his agenda but not addressed by my article.

My op-ed cited the Journal of Toxicology and Environmental Health study in the context that it is sure to rekindle the debate about vaccine safety. Mr. Salzberg's focus on this journal article confirms that indeed it has. I did not, however, as Mr. Salzberg contends, cite this article to support any "claims."

Mr. Salzberg is totally without accuracy when calls me an "anti-vaccine activist." Not true. Presenting solid facts about vaccines — 36 recommended doses before age 2 — provides information that can help improve our country's immunization efforts to ensure that children are both free from disease and free from adverse reactions to vaccination.

It is fine for Mr. Salzberg to have his own words and views. It is not fine for him to mischaracterize my words and views. I urge readers to read my actual article and draw their own conclusions.

Margaret Dunkle, Washington