As an infectious-disease specialist, I will be called on to be vaccinated early to counter any terrorist smallpox attack. I believe the chances of this are vanishingly small and that the policy is primarily an effort to spread fear and build support for a war with Iraq. If I am vaccinated, I will be complicit with a policy I morally oppose and unnecessarily endanger my own health. (The vaccine is one of the most dangerous available.) Yet I feel dutybound to be available to those suffering adverse effects from the vaccine. Should I be vaccinated? Hal Martin, M.D., M.P.H., Minneapolis

hile your decision has political implications, it is above all a medical matter. You are not being asked to endorse the president's Iraq policy but to decide if vaccination is called for in your circumstances. Believing as you do that there is no medical necessity, you have no ethical obligation to be vaccinated simply because the president urges it.

As a doctor, you can judge the risks of vaccination. As a citizen of a democracy, you must decide if the president has made a persuasive case that a smallpox attack is likely enough to justify that risk. If you and your colleagues overwhelmingly reject the president's call, this may indeed be interpreted as a rebuff of his policy, but that should be a byproduct of your decision, not your reason for making it.

Right now, you must weigh your duty to your fellow health-care workers, only a small percentage of whom are expected to become ill from the vaccine. This means that the vast majority of those health-care workers who choose to be vaccinated will be available to attend that ailing few -- a self-selecting, self-treating group -- and thus your participation is not essential.

You would face a tougher choice if the president called for the vaccination of the general population. You might feel an obligation to your longtime patients to be available to treat those affected by the vaccine. This would mean either being vaccinated yourself or remaining unvaccinated and accepting the hazard of exposure as a matter of conscience.

And if you are wrong and there is a smallpox attack? That would be horrific. But you cannot escape the burden of choice by simply following orders.

There is another aspect of this question that concerns not only physicians but all Americans. Financing an expensive smallpox vaccination program necessarily means neglecting many pressing medical problems, both here and abroad. In our era of tight budgets, deciding how to allocate health-care resources is a question with both moral and political dimensions.

I recently borrowed my brother's car. As I left the parking garage, a police car pulled me over. One headlight was out, and I received a ticket for $75. My brother said that he would repair the light, but he wants me to pay the ticket! I think he should pay it; after all, he lent me damaged goods! Who's right? Jennifer Wider, Brooklyn

If your brother knew the headlight was out but failed to tell you, he should cover the ticket. But if he didn't know, you're on your own. Unexpected breakage is a risk any driver faces, no matter the owner. And of course if he knew and he alerted you, you're doubly stuck -- with both the ticket and a flush of embarrassment for not heeding his warning.

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